Given the thermodynamic stability of the C(sp2)–O bond, the development of simple and efficient strategies for its functionalization holds significant practical value. In this study, we report an electroreductive, one-pot nickel-catalyzed cross-electrophile coupling (XEC) of aryl/alkenyl triflates with diverse (1°, 2°, and 3°) alkyl bromides. Rapid in situ generation of Ni0 species enables efficient activation of the C(sp2)–O bond, yielding a broad range of C(sp2)–C(sp3) coupling products. Notably, the ligand functions as an organo-mediator to assist alkyl halide activation and prevent the over-reduction of substrates. This protocol is distinguished by its broad substrate scope, scalability, and mild reaction conditions.
{"title":"Nickel-Catalyzed Electroreductive Cross-Electrophile Coupling of Aryl/Alkenyl Triflates with Alkyl Bromides Assisted by an Organo-Mediator","authors":"Yikun Ji,Xueting Zhang,Zhouhang Wang,Yaoyang Chen,Jinhui Hu,Yubing Huang","doi":"10.1021/acscatal.6c06705","DOIUrl":"https://doi.org/10.1021/acscatal.6c06705","url":null,"abstract":"Given the thermodynamic stability of the C(sp2)–O bond, the development of simple and efficient strategies for its functionalization holds significant practical value. In this study, we report an electroreductive, one-pot nickel-catalyzed cross-electrophile coupling (XEC) of aryl/alkenyl triflates with diverse (1°, 2°, and 3°) alkyl bromides. Rapid in situ generation of Ni0 species enables efficient activation of the C(sp2)–O bond, yielding a broad range of C(sp2)–C(sp3) coupling products. Notably, the ligand functions as an organo-mediator to assist alkyl halide activation and prevent the over-reduction of substrates. This protocol is distinguished by its broad substrate scope, scalability, and mild reaction conditions.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"79 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2026-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149248612","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-10-26DOI: 10.1021/acscatal.6c04944
Eli J. Mertick-Sykes,Shubhashree Pani,Ashley N. Ogorek,Sloan A. August,Georgia A. Apple,Emily M. Hwang,Elexi C. Kourtoglou,Gabriela P. Ruiz,Madeleine A. Wilson,Bryan C. Dickinson,Geoffrey C. Hoops,John J. Esteb,R. Jeremy Johnson,Jeffrey D. Martell
Directed evolution of enzymes is generally performed toward a specific substrate, which predictably improves enzyme activity toward the probe substrate. However, it is difficult to predict whether evolved enzymes will be selective or promiscuous toward other substrates. Multiplexed directed evolution can identify enzyme variants with selectivity/promiscuity across multiple substrates, but is typically performed using plate-based screening assays that are limited to testing a few hundred mutants. Combining substrate multiplexing with ultrahigh-throughput evolution technologies is a promising avenue for deeper exploration of the mutational landscape, but it has not been investigated whether enzymes evolved using multiplexed ultrahigh-throughput methods exhibit selectivity/promiscuity toward a broader scope of small-molecule substrates beyond the probes used during evolution. Here, we performed multiplexed ultrahigh-throughput evolution of Bacillus subtilis (BS2) esterase, merging yeast surface display with masked acid chloride probes, to identify a panel of mutants with improved selectivity toward the phenylcyclopropyl (pCP) ester protecting group relative to not only the probe substrate, but also a broad panel of 90 additional esters. Additionally, we applied the platform to identify a promiscuous mutant with improved activity across a broad substrate scope. Finally, we applied the highly pCP-selective BS2 variant, together with a selective variant for the methylcyclopropyl (mCP) ester protecting group, to demonstrate proximity labeling in mammalian cells with two orthogonal enzyme/probe systems, opening new opportunities in multiplexed proximity labeling. Overall, this study presents an efficacious method to identify enzyme variants with desired selectivity profiles that may be extended to multiple applications in chemical biology and synthesis.
{"title":"Multiplexed Ultrahigh-Throughput Evolution for Esterase Selectivity across a Broad Substrate Scope","authors":"Eli J. Mertick-Sykes,Shubhashree Pani,Ashley N. Ogorek,Sloan A. August,Georgia A. Apple,Emily M. Hwang,Elexi C. Kourtoglou,Gabriela P. Ruiz,Madeleine A. Wilson,Bryan C. Dickinson,Geoffrey C. Hoops,John J. Esteb,R. Jeremy Johnson,Jeffrey D. Martell","doi":"10.1021/acscatal.6c04944","DOIUrl":"https://doi.org/10.1021/acscatal.6c04944","url":null,"abstract":"Directed evolution of enzymes is generally performed toward a specific substrate, which predictably improves enzyme activity toward the probe substrate. However, it is difficult to predict whether evolved enzymes will be selective or promiscuous toward other substrates. Multiplexed directed evolution can identify enzyme variants with selectivity/promiscuity across multiple substrates, but is typically performed using plate-based screening assays that are limited to testing a few hundred mutants. Combining substrate multiplexing with ultrahigh-throughput evolution technologies is a promising avenue for deeper exploration of the mutational landscape, but it has not been investigated whether enzymes evolved using multiplexed ultrahigh-throughput methods exhibit selectivity/promiscuity toward a broader scope of small-molecule substrates beyond the probes used during evolution. Here, we performed multiplexed ultrahigh-throughput evolution of Bacillus subtilis (BS2) esterase, merging yeast surface display with masked acid chloride probes, to identify a panel of mutants with improved selectivity toward the phenylcyclopropyl (pCP) ester protecting group relative to not only the probe substrate, but also a broad panel of 90 additional esters. Additionally, we applied the platform to identify a promiscuous mutant with improved activity across a broad substrate scope. Finally, we applied the highly pCP-selective BS2 variant, together with a selective variant for the methylcyclopropyl (mCP) ester protecting group, to demonstrate proximity labeling in mammalian cells with two orthogonal enzyme/probe systems, opening new opportunities in multiplexed proximity labeling. Overall, this study presents an efficacious method to identify enzyme variants with desired selectivity profiles that may be extended to multiple applications in chemical biology and synthesis.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"13 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2026-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149248501","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Single-atom catalysts (SACs) have attracted considerable interest, displaying impressive performance for a wide plethora of electrocatalytic reactions. However, the important question whether isolated sites are always beneficial remains unresolved. Here, by using the hydrazine oxidation reaction (HzOR) as a model reaction, we examine how isolated single-atom metal sites restrict the adsorption mode of intermediates to the monodentate configuration, which leads to weak intermediate stabilization and poor reaction kinetics. This contrasts with bulk metal sites where availability of the bidentate adsorption configuration offers better intermediate stabilization and dehydrogenation kinetics. As a result, Ir, Pt, and Pd SACs were found to require high HzOR overpotentials of 0.90, 1.21, and 1.19 V at 3 mA cm–2, respectively. Comparatively, their Ir, Pt, Pd nanoparticle counterparts with similar metal loading exhibit considerably lower overpotentials of only 0.35, 0.83, and 0.64 V at 3 mA cm–2, respectively. Taken together, our work contributes towards a more complete understanding of SACs, emphasizing the importance of considering site structure and the mechanistic demands of the reaction.
单原子催化剂（SACs）在广泛的电催化反应中表现出令人印象深刻的性能，引起了人们的极大兴趣。然而，是否孤立的地点总是有益的重要问题仍然没有解决。本文以肼氧化反应（HzOR）为模型反应，研究了孤立的单原子金属位如何将中间体的吸附模式限制为单齿结构，从而导致中间体稳定性弱和反应动力学差。这与大块金属位置形成对比，在大块金属位置，双齿吸附结构的可用性提供了更好的中间稳定性和脱氢动力学。结果发现，Ir， Pt和Pd SACs在3 mA cm-2时分别需要0.90,1.21和1.19 V的高HzOR过电位。相比之下，具有相似金属负载的Ir， Pt， Pd纳米颗粒在3 mA cm-2下的过电位分别为0.35,0.83和0.64 V。综上所述，我们的工作有助于更全面地了解SACs，强调考虑位点结构和反应机制要求的重要性。
{"title":"Kinetic Limitations of Single-Atom Catalysts in Hydrazine Oxidation","authors":"Sibo Wang,Xingyu Wang,Jiguang Zhang,Shin-An Chen,Lo-Yueh Chang,Meng Wang,Ruoou Yang,Qin Yang,Shuo Chen,Ziyun Wang,Yanwei Lum","doi":"10.1021/acscatal.6c08099","DOIUrl":"https://doi.org/10.1021/acscatal.6c08099","url":null,"abstract":"Single-atom catalysts (SACs) have attracted considerable interest, displaying impressive performance for a wide plethora of electrocatalytic reactions. However, the important question whether isolated sites are always beneficial remains unresolved. Here, by using the hydrazine oxidation reaction (HzOR) as a model reaction, we examine how isolated single-atom metal sites restrict the adsorption mode of intermediates to the monodentate configuration, which leads to weak intermediate stabilization and poor reaction kinetics. This contrasts with bulk metal sites where availability of the bidentate adsorption configuration offers better intermediate stabilization and dehydrogenation kinetics. As a result, Ir, Pt, and Pd SACs were found to require high HzOR overpotentials of 0.90, 1.21, and 1.19 V at 3 mA cm–2, respectively. Comparatively, their Ir, Pt, Pd nanoparticle counterparts with similar metal loading exhibit considerably lower overpotentials of only 0.35, 0.83, and 0.64 V at 3 mA cm–2, respectively. Taken together, our work contributes towards a more complete understanding of SACs, emphasizing the importance of considering site structure and the mechanistic demands of the reaction.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"21 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2026-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149248615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Efficient interfacial electron transfer from light-harvesting semiconductors to molecular catalysts remains a major challenge in molecular–semiconductor hybrid photocatalytic CO2 reduction, particularly for narrow-bandgap semiconductors, whose reduced thermodynamic driving force often requires assistance from metallic electron-transfer mediators such as Ag. Here, we show that, despite its narrow bandgap of 2.1 eV, the layered perovskite oxynitride K2LaTa2O6N (KLTON) functions as an effective semiconductor support for a supramolecular RuRu′ CO2-reduction catalyst without relying on Ag nanoparticles. The RuRu′/KLTON hybrid selectively converted CO2 to formate under visible-light irradiation with >99% selectivity, a turnover number of 691, and an apparent quantum yield of 6.1 ± 0.6% at 420 nm. Loading a small amount of Ag further increased the turnover number to 1077, but this 1.5-fold enhancement was modest compared with the larger Ag-induced activity enhancements reported for several conventional oxynitride-based hybrids, highlighting the weak Ag dependence of the KLTON-based system. Spatial photodeposition of Ag and MnOx revealed spatially differentiated surface redox reactivity on the terraced layered structure of KLTON, while time-resolved microwave conductivity and transient infrared absorption measurements showed favorable photogenerated-carrier dynamics and demonstrated that Ag loading modifies the electron dynamics of KLTON. Time-resolved emission measurements further revealed an additional nonradiative decay pathway at the Ru(II) photosensitizer/KLTON interface, consistent with interfacial electronic interaction without uniquely assigning its microscopic origin. These results identify favorable carrier dynamics and weak Ag dependence as key features of the KLTON-based molecular hybrid and highlight layered narrow-bandgap mixed-anion semiconductors as promising support materials for visible-light-driven molecular photocatalysis.
{"title":"Favorable Carrier Dynamics in a Narrow-Gap Layered Oxynitride Enable Efficient Molecular Hybrid CO2 Photoreduction","authors":"Xian Zhang,Jo Onodera,Shuji Anabuki,Naoki Tarutani,Ryosuke Nishikubo,Takuto Soma,Shuwei Liu,Kiyofumi Katagiri,Akira Yamakata,Osamu Ishitani,Akinori Saeki,Kazuhiko Maeda","doi":"10.1021/acscatal.6c05897","DOIUrl":"https://doi.org/10.1021/acscatal.6c05897","url":null,"abstract":"Efficient interfacial electron transfer from light-harvesting semiconductors to molecular catalysts remains a major challenge in molecular–semiconductor hybrid photocatalytic CO2 reduction, particularly for narrow-bandgap semiconductors, whose reduced thermodynamic driving force often requires assistance from metallic electron-transfer mediators such as Ag. Here, we show that, despite its narrow bandgap of 2.1 eV, the layered perovskite oxynitride K2LaTa2O6N (KLTON) functions as an effective semiconductor support for a supramolecular RuRu′ CO2-reduction catalyst without relying on Ag nanoparticles. The RuRu′/KLTON hybrid selectively converted CO2 to formate under visible-light irradiation with >99% selectivity, a turnover number of 691, and an apparent quantum yield of 6.1 ± 0.6% at 420 nm. Loading a small amount of Ag further increased the turnover number to 1077, but this 1.5-fold enhancement was modest compared with the larger Ag-induced activity enhancements reported for several conventional oxynitride-based hybrids, highlighting the weak Ag dependence of the KLTON-based system. Spatial photodeposition of Ag and MnOx revealed spatially differentiated surface redox reactivity on the terraced layered structure of KLTON, while time-resolved microwave conductivity and transient infrared absorption measurements showed favorable photogenerated-carrier dynamics and demonstrated that Ag loading modifies the electron dynamics of KLTON. Time-resolved emission measurements further revealed an additional nonradiative decay pathway at the Ru(II) photosensitizer/KLTON interface, consistent with interfacial electronic interaction without uniquely assigning its microscopic origin. These results identify favorable carrier dynamics and weak Ag dependence as key features of the KLTON-based molecular hybrid and highlight layered narrow-bandgap mixed-anion semiconductors as promising support materials for visible-light-driven molecular photocatalysis.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"5 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2026-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149248613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Single-atom catalysts (SACs) are generally considered C1-selective in CO2/CO electroreduction, as spatially isolated sites cannot efficiently sustain adjacent CO-derived intermediates required for C─C coupling. Here we show that this selectivity bias is not intrinsic to atomically dispersed Cu, but depends on single-atom site density. Across a series of Cu–N3O catalysts with different Cu site densities, increasing site density drives a clear selectivity crossover from H2 and CH4 formation to C2+ products. The total C2+ Faradaic efficiency (FE) rises from 9.6% on the low-density to 78.1% on the high-density at 1 bar CO, and further reaches 87.7% at 7 bar CO, whereas the low-density remains C1-selective. In situ attenuated-total-reflection surface enhanced infrared absorption spectroscopy (ATR-SEIRAS) reveals that dense Cu single atoms sustain a larger *COatop population and simultaneously shift interfacial water from strongly hydrogen-bonded species towards free-water-rich configurations. Density functional theory (DFT) calculations show that higher site density stabilizes CO-containing surface states and lowers the barrier of the acetate-forming pathway. These findings identify a CO-rich and proton-accessible interfacial state that favors C─C coupling over C1 hydrogenation, establishing site density as a structural descriptor for multicarbon electrosynthesis on single-atom catalysts.
单原子催化剂（SACs）在CO2/CO电还原中通常被认为是c1选择性的，因为空间上孤立的位点不能有效地维持C─C偶联所需的相邻CO衍生中间体。在这里，我们发现这种选择性偏差不是原子分散Cu所固有的，而是取决于单原子位密度。在一系列Cu - n30催化剂中，不同Cu位密度的Cu - n30催化剂中，增加的位密度导致H2和CH4生成到C2+产物有明显的选择性交叉。总C2+法拉第效率（FE）从低密度时的9.6%上升到1 bar CO下的78.1%，在7 bar CO下达到87.7%，而低密度仍保持c1选择性。原位衰减全反射表面增强红外吸收光谱（ATR-SEIRAS）显示，致密的Cu单原子维持较大的* cotop居群，同时将界面水从强氢键态转变为富自由水构型。密度泛函理论（DFT）计算表明，较高的位点密度稳定了含co的表面态，降低了醋酸盐形成途径的势垒。这些发现确定了一种富含co且质子可接近的界面态，这种界面态有利于C─C偶联而不是C1加氢，从而确立了位点密度作为单原子催化剂上多碳电合成的结构描述符。
{"title":"Regulated Density of Atomic Cu Sites Dictates Switching from C1 to C2+ Products in CO Electroreduction","authors":"Rongxing Qiu,Jiaran Li,Jia Yu,Yuting Zhang,Jinlong Wan,Yin Li,Jingnan Wang,Jun Li,Shuliang Yang,Li Peng","doi":"10.1021/acscatal.6c06810","DOIUrl":"https://doi.org/10.1021/acscatal.6c06810","url":null,"abstract":"Single-atom catalysts (SACs) are generally considered C1-selective in CO2/CO electroreduction, as spatially isolated sites cannot efficiently sustain adjacent CO-derived intermediates required for C─C coupling. Here we show that this selectivity bias is not intrinsic to atomically dispersed Cu, but depends on single-atom site density. Across a series of Cu–N3O catalysts with different Cu site densities, increasing site density drives a clear selectivity crossover from H2 and CH4 formation to C2+ products. The total C2+ Faradaic efficiency (FE) rises from 9.6% on the low-density to 78.1% on the high-density at 1 bar CO, and further reaches 87.7% at 7 bar CO, whereas the low-density remains C1-selective. In situ attenuated-total-reflection surface enhanced infrared absorption spectroscopy (ATR-SEIRAS) reveals that dense Cu single atoms sustain a larger *COatop population and simultaneously shift interfacial water from strongly hydrogen-bonded species towards free-water-rich configurations. Density functional theory (DFT) calculations show that higher site density stabilizes CO-containing surface states and lowers the barrier of the acetate-forming pathway. These findings identify a CO-rich and proton-accessible interfacial state that favors C─C coupling over C1 hydrogenation, establishing site density as a structural descriptor for multicarbon electrosynthesis on single-atom catalysts.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"4 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2026-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149250877","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sluggish charge dynamics and poor *NO polarization at active sites hinder the efficiency of photocatalytic nitrate reduction to ammonia (PcNRA). To address these issues, an atomic-level regulation strategy synergizing facet engineering with axial coordination was developed. Specifically, isolated Cu sites were anchored onto an electron-rich, ultrathin BiVO4 substrate exposing (040) facets. Functionalized ligands featuring distinct donor heteroatoms (S, N, O) were then systematically introduced, yielding a series of single-atom catalysts (S/N/O-Cu/BVO) with tailored axial microenvironments. A comprehensive methodology combining multidimensional spectroscopy and computational chemistry was established to verify this single-atom axial coordination. Detailed analyses of characteristic binding energies and absorption edge shifts via X-ray photoelectron spectroscopy (XPS) and synchrotron X-ray absorption fine structure (XAFS) identified localized coordination field effects. Crucially, these effects are distinct from conventional electronic metal-support interactions (EMSI), providing spectroscopic confirmation of successful axial ligand incorporation and guiding the prediction of their configurations. Building upon these spectral findings, density functional theory (DFT) models were constructed and optimized, conclusively validating the asymmetric axial coordination configurations within the system, specifically Cu-S2O1, Cu-N2O1, and Cu-O4. Catalytic evaluations demonstrated that S-Cu/BVO achieves the highest ammonia yield at 435 μmol·h–1·g–1. In-situ spectroscopy and DFT calculations elucidated the multidimensional synergistic mechanism driving this enhanced activity: (1) The prominently exposed (040) facets act as an interfacial electron sink, efficiently directing photogenerated electrons toward the Cu sites; (2) The axial S ligands reconstruct the electronic structure of the Cu centers via strong orbital coupling, thereby improving effective orbital overlap with nitrate; (3) The resulting asymmetric Cu-NO-S bridging configuration polarizes the critical *NO intermediate, substantially lowering the kinetic barrier for the rate-determining step.
活性位点缓慢的电荷动力学和较差的*NO极化阻碍了光催化硝酸还原成氨（PcNRA）的效率。为了解决这些问题，开发了一种原子水平的调节策略，将面工程与轴向协调协同起来。具体来说，将分离的Cu位点固定在富电子的超薄BiVO4衬底上，暴露（040）面。然后系统地引入具有不同给体杂原子（S， N， O）的功能化配体，得到一系列具有定制轴向微环境的单原子催化剂（S/N/O- cu /BVO）。建立了多维光谱和计算化学相结合的综合方法来验证这种单原子轴向配位。通过x射线光电子能谱（XPS）和同步加速器x射线吸收精细结构（XAFS）对特征结合能和吸收边移进行了详细分析，确定了局域配位场效应。至关重要的是，这些效应与传统的电子金属支撑相互作用（EMSI）不同，为轴向配体的成功结合提供了光谱确认，并指导了其构型的预测。基于这些光谱发现，构建并优化了密度泛函理论（DFT）模型，最终验证了系统内的不对称轴向配位构型，特别是Cu-S2O1， Cu-N2O1和Cu-O4。催化评价表明，S-Cu/BVO在435 μmol·h-1·g-1时氨收率最高。原位光谱和DFT计算阐明了驱动这种增强活性的多重协同机制：(1)突出暴露的（040）面作为界面电子汇，有效地将光生电子引导到Cu位点；(2)轴向S配体通过强轨道耦合重建Cu中心的电子结构，从而提高了与硝酸盐的有效轨道重叠；(3)由此产生的不对称Cu-NO-S桥接构型使临界*NO中间体极化，大大降低了速率决定步骤的动力学势垒。
{"title":"Synergistic Facet Engineering and Axial Asymmetric Coordination of Single-Atom Cu Polarize Nitric Oxide Intermediates to Boost Photocatalytic Nitrate Reduction to Ammonia","authors":"Qiang Fu,Yue Meng,Zhiling Huang,Zheming Ni,Shengjie Xia","doi":"10.1021/acscatal.6c02659","DOIUrl":"https://doi.org/10.1021/acscatal.6c02659","url":null,"abstract":"Sluggish charge dynamics and poor *NO polarization at active sites hinder the efficiency of photocatalytic nitrate reduction to ammonia (PcNRA). To address these issues, an atomic-level regulation strategy synergizing facet engineering with axial coordination was developed. Specifically, isolated Cu sites were anchored onto an electron-rich, ultrathin BiVO4 substrate exposing (040) facets. Functionalized ligands featuring distinct donor heteroatoms (S, N, O) were then systematically introduced, yielding a series of single-atom catalysts (S/N/O-Cu/BVO) with tailored axial microenvironments. A comprehensive methodology combining multidimensional spectroscopy and computational chemistry was established to verify this single-atom axial coordination. Detailed analyses of characteristic binding energies and absorption edge shifts via X-ray photoelectron spectroscopy (XPS) and synchrotron X-ray absorption fine structure (XAFS) identified localized coordination field effects. Crucially, these effects are distinct from conventional electronic metal-support interactions (EMSI), providing spectroscopic confirmation of successful axial ligand incorporation and guiding the prediction of their configurations. Building upon these spectral findings, density functional theory (DFT) models were constructed and optimized, conclusively validating the asymmetric axial coordination configurations within the system, specifically Cu-S2O1, Cu-N2O1, and Cu-O4. Catalytic evaluations demonstrated that S-Cu/BVO achieves the highest ammonia yield at 435 μmol·h–1·g–1. In-situ spectroscopy and DFT calculations elucidated the multidimensional synergistic mechanism driving this enhanced activity: (1) The prominently exposed (040) facets act as an interfacial electron sink, efficiently directing photogenerated electrons toward the Cu sites; (2) The axial S ligands reconstruct the electronic structure of the Cu centers via strong orbital coupling, thereby improving effective orbital overlap with nitrate; (3) The resulting asymmetric Cu-NO-S bridging configuration polarizes the critical *NO intermediate, substantially lowering the kinetic barrier for the rate-determining step.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"16 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2026-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149248611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nonoxidative butane dehydrogenation offers a direct route to C4 olefins, yet it remains challenged by the need to promote C–H activation while ensuring olefin desorption and suppressing C–C cracking. Here, we report a mechanism-guided study that combines density functional theory calculations with experimental validation to rationally design Rh-based catalysts for butane dehydrogenation. A series of Rh models with distinct geometric configurations on a graphene surface, including isolated Rh atom, fully exposed Rh2 and Rh3 clusters, and extended Rh surfaces, were constructed to elucidate the structure–activity relationship. The calculations reveal a volcano-type dependence of dehydrogenation activity on the Rh geometric configuration. Fully exposed Rh3 clusters exhibit optimal energetics for sequential C–H activation, whereas isolated Rh atoms and Rh nanoparticles show inferior activity. Experimental studies on Rh/nanodiamond@graphene catalysts confirm the prediction, demonstrating that fully exposed Rh clusters with an average Rh–Rh coordination number of approximately 1.9 achieve the best balance between C–H activation, olefin desorption, and C–C bond cleavage suppression. This study highlights highly efficient Rh active sites by regulating the geometric configuration and electronic property and provides a general strategy for designing dehydrogenation catalysts.
{"title":"Mechanism-Driven Size Optimization of Fully Exposed Rh Cluster Catalysts for Butane Dehydrogenation","authors":"Xiaowen Chen,Xiaohai Wang,Doudou Wang,Tianyi Ruan,Xiangbin Cai,Feng Hong,Yang Si,Jingwang Zhang,Guodong Wen,Jiangyong Diao,Mi Peng,Geng Sun,Ding Ma,Hongyang Liu","doi":"10.1021/acscatal.6c06227","DOIUrl":"https://doi.org/10.1021/acscatal.6c06227","url":null,"abstract":"Nonoxidative butane dehydrogenation offers a direct route to C4 olefins, yet it remains challenged by the need to promote C–H activation while ensuring olefin desorption and suppressing C–C cracking. Here, we report a mechanism-guided study that combines density functional theory calculations with experimental validation to rationally design Rh-based catalysts for butane dehydrogenation. A series of Rh models with distinct geometric configurations on a graphene surface, including isolated Rh atom, fully exposed Rh2 and Rh3 clusters, and extended Rh surfaces, were constructed to elucidate the structure–activity relationship. The calculations reveal a volcano-type dependence of dehydrogenation activity on the Rh geometric configuration. Fully exposed Rh3 clusters exhibit optimal energetics for sequential C–H activation, whereas isolated Rh atoms and Rh nanoparticles show inferior activity. Experimental studies on Rh/nanodiamond@graphene catalysts confirm the prediction, demonstrating that fully exposed Rh clusters with an average Rh–Rh coordination number of approximately 1.9 achieve the best balance between C–H activation, olefin desorption, and C–C bond cleavage suppression. This study highlights highly efficient Rh active sites by regulating the geometric configuration and electronic property and provides a general strategy for designing dehydrogenation catalysts.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"2 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2026-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149248614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Quaternary stereocenters on densely functionalized furanoside frameworks are challenging to construct with high chemo-, regio-, and stereocontrol, especially in the presence of nitrogen-containing motifs and multiple downstream diversification handles. Here, we disclose a sequence-programmed three-component radical carboamination of reverse exo-glycals that provides modular access to C4-quaternary furanosides through a distinct radical retrosynthetic logic. In this photoredox process, an N-centered radical adds to an electron-rich reverse exo-glycal to form a pseudo-anomeric radical, which is then intercepted by a Giese acceptor, enabling concomitant C–N and C–C bond formation in a single step. The protocol accommodates diverse N-radical precursors and electron-deficient alkenes, is further extendable to distinct pyranose- and furanose-derived reverse exo-glycals, supports late-stage glyco-functionalization of structurally complex molecules, and furnishes a spiro-glycosyl donor on preparative scale. Subsequent Vorbrüggen glycosylation enables divergent entry to structurally distinct spironucleosides. Preliminary biological profiling of these compounds reveals a modest antiviral signal against influenza A (PR8) at 50 μM, supporting the utility of this platform for probing underexplored spironucleoside chemical space. Mechanistic experiments support the proposed photoredox-mediated radical relay, while DFT studies provide a plausible basis for the contrasting reactivity of representative N-radical precursors. Collectively, this work offers a concise and programmable strategy for the synthesis of quaternary-center furanosides and their downstream spirocyclic derivatives from readily available carbohydrate feedstocks.
{"title":"Photoredox-Mediated Three-Component Carboamination of Reverse Exo-Glycals: Modular Access to C4-Quaternary Furanosides and Spironucleosides","authors":"Yaying Li,Aoxin Guo,Shangjie Xu,Jingjing Cheng,Mengfei Yin,Li-Wen Zhang,Xiao-Lin Zhang,Kan Zhong,Chao Cai,Wei Wang,Ming Li,Han Ding,Xue-Wei Liu","doi":"10.1021/acscatal.6c06901","DOIUrl":"https://doi.org/10.1021/acscatal.6c06901","url":null,"abstract":"Quaternary stereocenters on densely functionalized furanoside frameworks are challenging to construct with high chemo-, regio-, and stereocontrol, especially in the presence of nitrogen-containing motifs and multiple downstream diversification handles. Here, we disclose a sequence-programmed three-component radical carboamination of reverse exo-glycals that provides modular access to C4-quaternary furanosides through a distinct radical retrosynthetic logic. In this photoredox process, an N-centered radical adds to an electron-rich reverse exo-glycal to form a pseudo-anomeric radical, which is then intercepted by a Giese acceptor, enabling concomitant C–N and C–C bond formation in a single step. The protocol accommodates diverse N-radical precursors and electron-deficient alkenes, is further extendable to distinct pyranose- and furanose-derived reverse exo-glycals, supports late-stage glyco-functionalization of structurally complex molecules, and furnishes a spiro-glycosyl donor on preparative scale. Subsequent Vorbrüggen glycosylation enables divergent entry to structurally distinct spironucleosides. Preliminary biological profiling of these compounds reveals a modest antiviral signal against influenza A (PR8) at 50 μM, supporting the utility of this platform for probing underexplored spironucleoside chemical space. Mechanistic experiments support the proposed photoredox-mediated radical relay, while DFT studies provide a plausible basis for the contrasting reactivity of representative N-radical precursors. Collectively, this work offers a concise and programmable strategy for the synthesis of quaternary-center furanosides and their downstream spirocyclic derivatives from readily available carbohydrate feedstocks.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"253 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2026-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149241224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-10-25DOI: 10.1021/acscatal.6c06766
Raymond Z. Lo,Simone Baldon,Luca Dell’Amico,Matthew S. Sigman,Cristian Rosso
Enantioselective dual catalysis represents a powerful strategy for the preparation of functionally dense optically active compounds. Photocatalysis, paired with organocatalysis, undeniably represents a popular choice that takes advantage of radical and polar reactivity for crafting challenging bonds. Despite the interest in this methodology, the detailed analysis of the effects governing selectivity between the two catalytic cycles has not been extensively studied. Herein, we report a data-driven mechanistic study campaign to disclose the factors that influence the enantioselectivity of a photo-organocatalytic alkylation of indoles. Data science tools were used to generate a virtual library of potential substrates, thus ensuring the selection of a statistically diverse training set. Subsequent multivariate linear regression (MLR) analysis led to the identification of substrate electronic features as the key factor affecting the stereochemical outcome. Moreover, comprehensive mechanistic experiments unveiled the key role of the in situ generated oxindole intermediate that connects the two catalytic cycles in determining the observed selectivity. These findings lay the foundation for developing asymmetric dual catalytic transformations of synthetic relevance and provide a general platform for interrogating other complex catalytic systems.
{"title":"Data-Driven Investigation of Asymmetric Photo-Organocatalyzed Alkylation of Indoles","authors":"Raymond Z. Lo,Simone Baldon,Luca Dell’Amico,Matthew S. Sigman,Cristian Rosso","doi":"10.1021/acscatal.6c06766","DOIUrl":"https://doi.org/10.1021/acscatal.6c06766","url":null,"abstract":"Enantioselective dual catalysis represents a powerful strategy for the preparation of functionally dense optically active compounds. Photocatalysis, paired with organocatalysis, undeniably represents a popular choice that takes advantage of radical and polar reactivity for crafting challenging bonds. Despite the interest in this methodology, the detailed analysis of the effects governing selectivity between the two catalytic cycles has not been extensively studied. Herein, we report a data-driven mechanistic study campaign to disclose the factors that influence the enantioselectivity of a photo-organocatalytic alkylation of indoles. Data science tools were used to generate a virtual library of potential substrates, thus ensuring the selection of a statistically diverse training set. Subsequent multivariate linear regression (MLR) analysis led to the identification of substrate electronic features as the key factor affecting the stereochemical outcome. Moreover, comprehensive mechanistic experiments unveiled the key role of the in situ generated oxindole intermediate that connects the two catalytic cycles in determining the observed selectivity. These findings lay the foundation for developing asymmetric dual catalytic transformations of synthetic relevance and provide a general platform for interrogating other complex catalytic systems.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"37 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2026-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149241221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-10-25DOI: 10.1021/acscatal.6c05148
Christina M. Wark Kessler,Keyvan Malaie,Jannelle Casanova-Rañoa,Meheryar R. Kasad,Uwe Schröder,Christopher M. Saffron,James E. Jackson,Scott Calabrese Barton
Bio-oil derived from lignocellulosic biomass represents an alternative to fossil fuels as an energy source and chemical feedstock. Fast pyrolysis of lignocellulosic biomass yields a rich mixture of oxygenated organic species with low energy density and low stability, which can be electrochemically upgraded to increase energy density and stability and produce value-added chemicals. Here, we focus on electrocatalytic hydrotreatment of furfural (FF) and 4-propylphenol (4-PP), two constituents of raw bio-oil. In a binary mixture, the presence of FF has been shown to inhibit the reduction of 4-PP. The underlying mechanisms of these competing reactions are probed using density functional theory (DFT) and experimental electrochemical deposition techniques. The binding energies of FF and 4-PP, as well as their respective reduction products and associated reaction thermodynamics, are examined comparatively on multiple facets of single-crystal platinum and ruthenium catalysts. FF is shown to bind competitively compared to 4-PP, particularly on Pt(111) and Ru(0001), and hydrogenation products such as tetrahydrofurfuryl alcohol (THFA) and 4-propylcyclohexanol (4-PCOL) were found to bind less strongly to the surfaces than the reactants. FF reduction side products, including dimers furoin (FUI) and hydrofuroin (HF), were also found to bind competitively with 4-PP. No thermodynamic barriers were observed for FF hydrogenation to THFA, whereas 4-PCOL formation is favored on Pt facets, and propylcyclohexane (PC) formation is favored on Ru. The presence of barriers to 4-PP hydrogenation indicates that FF hydrogenation is thermodynamically favored on Pt and Ru. Further, limiting potential calculations suggest that the FF reduction pathways are generally favorable around 0 V vs. RHE. In contrast, the 4-PP reduction pathways require a more cathodic bias, achieved at potentials less than -0.1 V vs. RHE. The adsorption behavior of FF-derived reduction products on polycrystalline Pt is experimentally validated using a Quartz Crystal Microbalance (QCM). Such experiments yield estimates of aqueous-phase free energies of adsorption, which are compared with computational results that are correlated to the aqueous phase. Overall, the DFT model results suggest that the observed inhibition of 4-PP by FF is due to competitive adsorption and favorable FF reaction thermodynamics.
{"title":"Quantum Chemical Insight into Species Competition in Electrochemical Upgrading of Bio-Oil","authors":"Christina M. Wark Kessler,Keyvan Malaie,Jannelle Casanova-Rañoa,Meheryar R. Kasad,Uwe Schröder,Christopher M. Saffron,James E. Jackson,Scott Calabrese Barton","doi":"10.1021/acscatal.6c05148","DOIUrl":"https://doi.org/10.1021/acscatal.6c05148","url":null,"abstract":"Bio-oil derived from lignocellulosic biomass represents an alternative to fossil fuels as an energy source and chemical feedstock. Fast pyrolysis of lignocellulosic biomass yields a rich mixture of oxygenated organic species with low energy density and low stability, which can be electrochemically upgraded to increase energy density and stability and produce value-added chemicals. Here, we focus on electrocatalytic hydrotreatment of furfural (FF) and 4-propylphenol (4-PP), two constituents of raw bio-oil. In a binary mixture, the presence of FF has been shown to inhibit the reduction of 4-PP. The underlying mechanisms of these competing reactions are probed using density functional theory (DFT) and experimental electrochemical deposition techniques. The binding energies of FF and 4-PP, as well as their respective reduction products and associated reaction thermodynamics, are examined comparatively on multiple facets of single-crystal platinum and ruthenium catalysts. FF is shown to bind competitively compared to 4-PP, particularly on Pt(111) and Ru(0001), and hydrogenation products such as tetrahydrofurfuryl alcohol (THFA) and 4-propylcyclohexanol (4-PCOL) were found to bind less strongly to the surfaces than the reactants. FF reduction side products, including dimers furoin (FUI) and hydrofuroin (HF), were also found to bind competitively with 4-PP. No thermodynamic barriers were observed for FF hydrogenation to THFA, whereas 4-PCOL formation is favored on Pt facets, and propylcyclohexane (PC) formation is favored on Ru. The presence of barriers to 4-PP hydrogenation indicates that FF hydrogenation is thermodynamically favored on Pt and Ru. Further, limiting potential calculations suggest that the FF reduction pathways are generally favorable around 0 V vs. RHE. In contrast, the 4-PP reduction pathways require a more cathodic bias, achieved at potentials less than -0.1 V vs. RHE. The adsorption behavior of FF-derived reduction products on polycrystalline Pt is experimentally validated using a Quartz Crystal Microbalance (QCM). Such experiments yield estimates of aqueous-phase free energies of adsorption, which are compared with computational results that are correlated to the aqueous phase. Overall, the DFT model results suggest that the observed inhibition of 4-PP by FF is due to competitive adsorption and favorable FF reaction thermodynamics.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"22 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2026-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149241223","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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