Pub Date : 2025-06-20DOI: 10.1021/acscatal.5c01633
Guangming Cai, Ya-Huei Cathy Chin
Electronic properties of redox and Lewis acid sites on bifunctional metal oxides are inherently correlated to each other, a phenomenon that has long been recognized but not yet explicitly and quantitatively illustrated. Using alkanol oxidative dehydrogenation (ODH) and inter- and intramolecular dehydration (inter- and intra-DEH) kinetics as the respective thermochemical/electronic proxies for redox and Lewis acid sites, we elucidate the thermochemical and electronic correlations of these two types of sites on Co<sub><i>y</i></sub>MoO<sub><i>x</i></sub> domains with Co-to-Mo atomic ratio (<i>y</i>) varying from 0 to 1. At redox sites (O*), alkanol ODH occurs via a late, kinetically relevant C<sub>α</sub>–H scission transition state [O···<b>H···</b>RH<b>C</b>O···M<sup><i>n</i>+</sup>]<sup>‡</sup>, involving a net H atom (H<sup>•</sup>), arising from an electron (e<sup>–</sup>) and a proton (H<sup>+</sup>) transfer to a redox site, making hydrogen addition energy (HAE) as the kinetic descriptor, encapsulating the negative of electron (–EA<sub>MO</sub>) and proton (–PA<sub>O<sup>–</sup></sub>) affinities of catalysts. At Lewis acid sites, alkanol inter-DEH proceeds via S<sub>N</sub>2-type substitution with the [O<sup>δ−</sup>···<b>H···</b>RH<sub>2</sub>C<b>O···C</b>H<sub>2</sub>R<b>···O</b>H···M<sup>δ+</sup>]<sup>‡</sup> transition state, while intra-DEH, whether uni- or bimolecular, occurs via E2-type elimination through the [O<sup>δ−</sup>···<b>H···</b>R′H<b>C</b>H<sub>2</sub><b>C</b><sup><b>⊕</b></sup><b>···</b><sup><b>⊖</b></sup><b>O</b>H···M<sup>δ+</sup>]<sup>‡</sup> and [RH<sub>2</sub>C(H)O<sup>δ−</sup>···<b>H···</b>R′H<b>C</b>H<sub>2</sub><b>C</b><sup><b>⊕</b></sup><b>···</b><sup><b>⊖</b></sup><b>O</b>H···M<sup>δ+</sup>]<sup>‡</sup> transition states. These DEH pathways involve C–O scission in their respective transition states, where an electron and a <sup>•</sup>OH radical transfer as a <sup>⊖</sup>OH group to the Lewis acid center (<b>M</b><sup><b>δ+</b></sup>–O<sup>δ–</sup>). Consequently, the negative <sup>⊖</sup>OH affinity (–HA<sub>⊖OH</sub>) serves as an incomplete kinetic descriptor, encapsulating the same negative electron affinity and the negative <sup>•</sup>OH affinity (–HA<sub>•OH</sub>) of catalysts. The common electron transfer during the evolution of all these transition states in alkanol ODH and DEH entails the electron affinity of metal oxides to determine their relative activation enthalpies. On Co<sub><i>y</i></sub>MoO<sub><i>x</i></sub>, introducing Co cations as electronic perturbators increases the electron affinity of these oxides, thereby reducing both HAE at redox sites and –HA<sub>⊖OH</sub> at Lewis acid sites, which proportionally decreases the activation enthalpies for C<sub>α</sub>–H scission in methanol, ethanol, <i>n</i>-propanol, and <i>n</i>-butanol ODH; C–O formation in methanol and ethanol inter-DEH; and C<sub>β</sub>–H scission in uni- and bimolecular <i>n</i>-propanol and <i>n</i>-butanol intra-DEH, as th
{"title":"Thermochemical and Kinetic Correlations of Redox and Lewis Sites on Cobalt–Molybdenum Oxides: Illustrated with Alkanol-O2 Catalysis","authors":"Guangming Cai, Ya-Huei Cathy Chin","doi":"10.1021/acscatal.5c01633","DOIUrl":"https://doi.org/10.1021/acscatal.5c01633","url":null,"abstract":"Electronic properties of redox and Lewis acid sites on bifunctional metal oxides are inherently correlated to each other, a phenomenon that has long been recognized but not yet explicitly and quantitatively illustrated. Using alkanol oxidative dehydrogenation (ODH) and inter- and intramolecular dehydration (inter- and intra-DEH) kinetics as the respective thermochemical/electronic proxies for redox and Lewis acid sites, we elucidate the thermochemical and electronic correlations of these two types of sites on Co<sub><i>y</i></sub>MoO<sub><i>x</i></sub> domains with Co-to-Mo atomic ratio (<i>y</i>) varying from 0 to 1. At redox sites (O*), alkanol ODH occurs via a late, kinetically relevant C<sub>α</sub>–H scission transition state [O···<b>H···</b>RH<b>C</b>O···M<sup><i>n</i>+</sup>]<sup>‡</sup>, involving a net H atom (H<sup>•</sup>), arising from an electron (e<sup>–</sup>) and a proton (H<sup>+</sup>) transfer to a redox site, making hydrogen addition energy (HAE) as the kinetic descriptor, encapsulating the negative of electron (–EA<sub>MO</sub>) and proton (–PA<sub>O<sup>–</sup></sub>) affinities of catalysts. At Lewis acid sites, alkanol inter-DEH proceeds via S<sub>N</sub>2-type substitution with the [O<sup>δ−</sup>···<b>H···</b>RH<sub>2</sub>C<b>O···C</b>H<sub>2</sub>R<b>···O</b>H···M<sup>δ+</sup>]<sup>‡</sup> transition state, while intra-DEH, whether uni- or bimolecular, occurs via E2-type elimination through the [O<sup>δ−</sup>···<b>H···</b>R′H<b>C</b>H<sub>2</sub><b>C</b><sup><b>⊕</b></sup><b>···</b><sup><b>⊖</b></sup><b>O</b>H···M<sup>δ+</sup>]<sup>‡</sup> and [RH<sub>2</sub>C(H)O<sup>δ−</sup>···<b>H···</b>R′H<b>C</b>H<sub>2</sub><b>C</b><sup><b>⊕</b></sup><b>···</b><sup><b>⊖</b></sup><b>O</b>H···M<sup>δ+</sup>]<sup>‡</sup> transition states. These DEH pathways involve C–O scission in their respective transition states, where an electron and a <sup>•</sup>OH radical transfer as a <sup>⊖</sup>OH group to the Lewis acid center (<b>M</b><sup><b>δ+</b></sup>–O<sup>δ–</sup>). Consequently, the negative <sup>⊖</sup>OH affinity (–HA<sub>⊖OH</sub>) serves as an incomplete kinetic descriptor, encapsulating the same negative electron affinity and the negative <sup>•</sup>OH affinity (–HA<sub>•OH</sub>) of catalysts. The common electron transfer during the evolution of all these transition states in alkanol ODH and DEH entails the electron affinity of metal oxides to determine their relative activation enthalpies. On Co<sub><i>y</i></sub>MoO<sub><i>x</i></sub>, introducing Co cations as electronic perturbators increases the electron affinity of these oxides, thereby reducing both HAE at redox sites and –HA<sub>⊖OH</sub> at Lewis acid sites, which proportionally decreases the activation enthalpies for C<sub>α</sub>–H scission in methanol, ethanol, <i>n</i>-propanol, and <i>n</i>-butanol ODH; C–O formation in methanol and ethanol inter-DEH; and C<sub>β</sub>–H scission in uni- and bimolecular <i>n</i>-propanol and <i>n</i>-butanol intra-DEH, as th","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"4 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144335214","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 : 2025-06-20DOI: 10.1021/acscatal.5c01532
Yinghui Feng, Xin Yan, Mingzhe Ma, Ruyi Chen, Chuanxi Zhang, Yalong Cong, Bohuan Fang, Chunchi Chen, Longhai Dai, Hao Li, Haiming Jiang, Hong Sun, Hao Wei, Reyting Guo, Bei Gao, John Z. H. Zhang, Lujia Zhang
One-step amine–carboxyl dehydration condensation in cells (100% aqueous phase) is the most efficient and sustainable natural method for peptide and protein synthesis. However, most peptide ligases need modifications of substrates at the C- or N-terminal. To create this ligase, we engineered a “water-shielded” reaction chamber in protease subtilisin-P225A through precise polarization calculation using our self-developed PPC force field, thereby converting the hydrolysis reaction to a ligation reaction. We marked the first success and achieved 12 monomutants at first-round mutagenesis. The combined mutant P225A/N62L/S63L/Y217L/N218F with the highest activity was named Aqualigase. The X-ray structural and HDX-MS analysis confirmed a 20%–50% reduction in proton exchange and 50% elimination of water from the active site, demonstrating the success of the “water-shielding effect”. With Aqualigase/N158E, we successfully achieved the one-step synthesis of teriparatide, addressing the long-standing challenges in long-chain peptide or protein ligation. Notably, Aqualigase was also able to catalyze dealcoholizing ligation, transamidation, and esterification reactions. Its suitability for the length, size, and even the N- or C-terminal sequence composition of peptides or protein provides a huge scope for in situ protein conjunction in cells and peptide synthesis in industry.
{"title":"Aqualigase: A Star Enzyme for One-Step Peptide Bond Dehydration Condensation in a Nature Aqueous Phase","authors":"Yinghui Feng, Xin Yan, Mingzhe Ma, Ruyi Chen, Chuanxi Zhang, Yalong Cong, Bohuan Fang, Chunchi Chen, Longhai Dai, Hao Li, Haiming Jiang, Hong Sun, Hao Wei, Reyting Guo, Bei Gao, John Z. H. Zhang, Lujia Zhang","doi":"10.1021/acscatal.5c01532","DOIUrl":"https://doi.org/10.1021/acscatal.5c01532","url":null,"abstract":"One-step amine–carboxyl dehydration condensation in cells (100% aqueous phase) is the most efficient and sustainable natural method for peptide and protein synthesis. However, most peptide ligases need modifications of substrates at the C- or N-terminal. To create this ligase, we engineered a “water-shielded” reaction chamber in protease subtilisin-P225A through precise polarization calculation using our self-developed PPC force field, thereby converting the hydrolysis reaction to a ligation reaction. We marked the first success and achieved 12 monomutants at first-round mutagenesis. The combined mutant P225A/N62L/S63L/Y217L/N218F with the highest activity was named Aqualigase. The X-ray structural and HDX-MS analysis confirmed a 20%–50% reduction in proton exchange and 50% elimination of water from the active site, demonstrating the success of the “water-shielding effect”. With Aqualigase/N158E, we successfully achieved the one-step synthesis of teriparatide, addressing the long-standing challenges in long-chain peptide or protein ligation. Notably, Aqualigase was also able to catalyze dealcoholizing ligation, transamidation, and esterification reactions. Its suitability for the length, size, and even the N- or C-terminal sequence composition of peptides or protein provides a huge scope for in situ protein conjunction in cells and peptide synthesis in industry.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"25 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144329305","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 : 2025-06-20DOI: 10.1021/acscatal.5c02570
Manish Kothakonda, Sarah LaCroix, Chengyu Zhou, Ji Yang, Ji Su, Qing Zhao
Direct methane conversion to liquid fuels or value-added chemicals is a promising technology to utilize natural resources without resorting to further petroleum extraction. However, discovering efficient catalysts for this reaction is challenging due to either coke formation or unfavorable C–H bond activation. Herein, we design single-atom alloy (SAA) catalysts to simultaneously eliminate the above two bottlenecks based on mechanism-guided strategies: (1) the active single atom enables favorable C–H bond breaking and (2) the less reactive host metal facilitates C–C coupling and thus avoids strong binding of carbonaceous species. Employing electronic structure theory calculations, we screened the stability of multiple SAAs with 3d-5d transition metals atomically dispersed on a copper surface in terms of avoiding dopant aggregation and segregation. We then evaluated reactivities of the stable SAAs as catalysts for direct methane conversion to C2 products, including methane dehydrogenation and C–C coupling mechanisms. Combining selectivity analysis with kinetic modeling, we predicted that nickel dispersed on copper, i.e., Ni/Cu SAA, is a highly active and selective catalyst that can efficiently transform methane to ethylene. This work designs efficient SAA catalysts for direct methane activation and provides chemical insights into engineering compositions of SAAs to tune their catalytic performances.
{"title":"Discovering Ni/Cu Single-Atom Alloy as a Highly Active and Selective Catalyst for Direct Methane Conversion to Ethylene: A First-Principles Kinetic Study","authors":"Manish Kothakonda, Sarah LaCroix, Chengyu Zhou, Ji Yang, Ji Su, Qing Zhao","doi":"10.1021/acscatal.5c02570","DOIUrl":"https://doi.org/10.1021/acscatal.5c02570","url":null,"abstract":"Direct methane conversion to liquid fuels or value-added chemicals is a promising technology to utilize natural resources without resorting to further petroleum extraction. However, discovering efficient catalysts for this reaction is challenging due to either coke formation or unfavorable C–H bond activation. Herein, we design single-atom alloy (SAA) catalysts to simultaneously eliminate the above two bottlenecks based on mechanism-guided strategies: (1) the active single atom enables favorable C–H bond breaking and (2) the less reactive host metal facilitates C–C coupling and thus avoids strong binding of carbonaceous species. Employing electronic structure theory calculations, we screened the stability of multiple SAAs with 3d-5d transition metals atomically dispersed on a copper surface in terms of avoiding dopant aggregation and segregation. We then evaluated reactivities of the stable SAAs as catalysts for direct methane conversion to C<sub>2</sub> products, including methane dehydrogenation and C–C coupling mechanisms. Combining selectivity analysis with kinetic modeling, we predicted that nickel dispersed on copper, i.e., Ni/Cu SAA, is a highly active and selective catalyst that can efficiently transform methane to ethylene. This work designs efficient SAA catalysts for direct methane activation and provides chemical insights into engineering compositions of SAAs to tune their catalytic performances.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"237 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144329310","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}
Developing noniridium-based catalysts is highly desired yet challenging for the oxygen evolution reaction (OER) in proton exchange membrane electrolyzers and other devices. In this study, uncoordinated RuOx clusters with adjacent atomically dispersed Ru sites on the N-doped carbon support (RuSAC@RuOx/N–C) is reported for OER in acids, delivering an overpotential of 186 mV at 10 mA cmgeo–2 and steady operation for 519 h in 0.5 M H2SO4, significantly outperforming commercial RuO2 with an overpotential of 326 mV and stability less than 5 h. Physical characterizations, poison experiments, and theoretical results reveal that uncoordinated RuOx clusters act as the dominant active sites; the neighboring Ru sites effectively increase the Ru 4d–O 2p orbital hybridization in RuOx, which in turn increases the electron delocalization of the Ru sites and optimizes the binding strength with intermediates to enhance catalytic activity. Importantly, the Ru single sites efficiently suppress the thermal vibrations of the Ru–O bonds in RuOx clusters, reducing the tendency for Ru atom detachment and promoting stability performance. This work sheds light on the unique function of metal single sites as immobilizers for stabilizing metal oxides and opens pathways to design stable catalyst materials for reactions under harsh conditions.
开发非铱基催化剂是质子交换膜电解槽和其他装置中析氧反应（OER）的迫切需求和挑战。在这项研究中，在n掺杂碳载体（RuSAC@RuOx/ N-C）上，具有相邻原子分散Ru位点的不协调的RuOx簇在酸中的OER，在10 mA cmo - 2下提供186 mV的过电位，在0.5 M H2SO4中稳定运行519小时，显著优于商业RuO2的过电位326 mV，稳定性小于5小时。理论结果表明，不协调的RuOx簇是主要的活性位点；邻近的Ru位点有效地增加了RuOx中Ru的4d-O 2p轨道杂化，从而增加了Ru位点的电子离域，优化了与中间体的结合强度，从而提高了催化活性。重要的是，Ru单位点有效地抑制了RuOx簇中Ru - o键的热振动，减少了Ru原子脱离的趋势，提高了稳定性。这项工作揭示了金属单位点作为稳定金属氧化物的固定剂的独特功能，并为设计在恶劣条件下反应的稳定催化剂材料开辟了途径。
{"title":"Harmonizing Ruthenium Atom-Cluster Moieties for Stable Proton Exchange Membrane Water Electrolysis","authors":"Chengli Rong, Jun Jia, Weiwei Li, Sicheng Wu, Qian Sun, Chen Jia, Soshan Cheong, Yuzheng Guo, Chuan Zhao","doi":"10.1021/acscatal.5c02132","DOIUrl":"https://doi.org/10.1021/acscatal.5c02132","url":null,"abstract":"Developing noniridium-based catalysts is highly desired yet challenging for the oxygen evolution reaction (OER) in proton exchange membrane electrolyzers and other devices. In this study, uncoordinated RuO<sub><i>x</i></sub> clusters with adjacent atomically dispersed Ru sites on the N-doped carbon support (Ru<sub>SAC</sub>@RuO<sub><i>x</i></sub>/N–C) is reported for OER in acids, delivering an overpotential of 186 mV at 10 mA cm<sub>geo</sub><sup>–2</sup> and steady operation for 519 h in 0.5 M H<sub>2</sub>SO<sub>4</sub>, significantly outperforming commercial RuO<sub>2</sub> with an overpotential of 326 mV and stability less than 5 h. Physical characterizations, poison experiments, and theoretical results reveal that uncoordinated RuO<sub><i>x</i></sub> clusters act as the dominant active sites; the neighboring Ru sites effectively increase the Ru 4d–O 2p orbital hybridization in RuO<sub><i>x</i></sub>, which in turn increases the electron delocalization of the Ru sites and optimizes the binding strength with intermediates to enhance catalytic activity. Importantly, the Ru single sites efficiently suppress the thermal vibrations of the Ru–O bonds in RuO<sub><i>x</i></sub> clusters, reducing the tendency for Ru atom detachment and promoting stability performance. This work sheds light on the unique function of metal single sites as immobilizers for stabilizing metal oxides and opens pathways to design stable catalyst materials for reactions under harsh conditions.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"7 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144335215","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 : 2025-06-20DOI: 10.1021/acscatal.5c03462
Jun Yang, Yuling Zhu, Yunxi Han, Han Ke, Jing Zhang, Ming-Wei Wang, Xiaoguang Lei
Trichothecenes, particularly T-2 toxin (T-2), pose significant threats to food safety as well as to both animal and human health. Although Fhb7 and its variants have been utilized for deoxynivalenol degradation, no enzyme with efficient T-2 degradation activity has been reported. Herein, we generated five enzymes derived from Fhb7 that are capable of T-2 degradation via ancestral sequence reconstruction. Among these, N1, N2, and N4 exhibited superior catalytic activity toward T-2 compared to the parent enzyme Fhb7 and its variants. Structural analyses revealed that residue F27 provides a hydrophobic environment for accommodation of the unique 3-methylbutyryl group of T-2. In addition, the long insertion loop of N2 plays a key role in its improved substrate preference. Furthermore, all the ancestors displayed remarkable thermostability, with N2 and N4 displaying superior thermal tolerance (Tm values are 54 and 59 °C, respectively, and their half-life times are longer than 90 h), positioning them as a promising candidate for industrial applications. This work introduces a promising enzymatic approach for T-2 degradation and lays a foundation for developing robust biocatalysts for the environmental and industrial bioremediation of mycotoxins.
{"title":"Developing Fhb7-Derived Enzymes with High Thermostability for Detoxification of T-2 Toxin through Ancestral Sequence Reconstruction","authors":"Jun Yang, Yuling Zhu, Yunxi Han, Han Ke, Jing Zhang, Ming-Wei Wang, Xiaoguang Lei","doi":"10.1021/acscatal.5c03462","DOIUrl":"https://doi.org/10.1021/acscatal.5c03462","url":null,"abstract":"Trichothecenes, particularly T-2 toxin (T-2), pose significant threats to food safety as well as to both animal and human health. Although Fhb7 and its variants have been utilized for deoxynivalenol degradation, no enzyme with efficient T-2 degradation activity has been reported. Herein, we generated five enzymes derived from Fhb7 that are capable of T-2 degradation via ancestral sequence reconstruction. Among these, N1, N2, and N4 exhibited superior catalytic activity toward T-2 compared to the parent enzyme Fhb7 and its variants. Structural analyses revealed that residue F27 provides a hydrophobic environment for accommodation of the unique 3-methylbutyryl group of T-2. In addition, the long insertion loop of N2 plays a key role in its improved substrate preference. Furthermore, all the ancestors displayed remarkable thermostability, with N2 and N4 displaying superior thermal tolerance (<i>T</i><sub>m</sub> values are 54 and 59 °C, respectively, and their half-life times are longer than 90 h), positioning them as a promising candidate for industrial applications. This work introduces a promising enzymatic approach for T-2 degradation and lays a foundation for developing robust biocatalysts for the environmental and industrial bioremediation of mycotoxins.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"36 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144335217","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}
The electrochemical nitrate reduction (NO3R) for ammonia synthesis holds promise for utilizing NO3– pollutants in water under ambient conditions. In the multielectron transfer process of NO3– anions transforming into ammonia, counter-cations play a critical role in influencing the interactions of anions and intermediates. Here, we investigated the impact of Cs+ ions on the electropolished flat copper (Cu) (100) surface during NO3R. Our results show that the presence of Cs+ leads to a significant decline in Cu activity, with an approximately 8-fold decrease in the partial current density for NH3 and an increase in interfacial resistance compared to using K+. Operando electrochemical Raman spectroscopy revealed the formation of oxygen and hydroxide species adsorbed on the surface (Cu-*O and Cu-*OH, the asterisk symbol indicates surface adsorption), alongside a decrease in the signals of NO3– intermediates in the presence of Cs+. Isotope labeling experiments with N18O3– identified a key deoxygenation pathway, involving the formation of N18O2 and 18O species. This deactivated Cu surface, resulting from the accumulation of adsorbed oxygen species, was pronounced under alkaline conditions and was consistently observed on other Cu surface facets, including Cu (111). Density functional theory (DFT) calculations explained how the stabilization of oxygen atoms (*O) on the Cu surface is due to weak hydrogen bonding with hydrated waters of Cs+ ions, whereas the stronger hydrogen bonding observed with K+ facilitates oxygen removal. Our findings offer mechanistic insights into the oxygen poisoning of Cu surfaces and highlight the detrimental effects of Cs+ on NO3R.
{"title":"Oxygen Poisoning of Copper Surfaces in the Presence of Cesium Ions during Electrochemical Nitrate Reduction to Ammonia","authors":"Minyoung Shim, Jinyoung Ko, Yohan Kim, Yousung Jung, Hye Ryung Byon","doi":"10.1021/acscatal.5c02252","DOIUrl":"https://doi.org/10.1021/acscatal.5c02252","url":null,"abstract":"The electrochemical nitrate reduction (NO<sub>3</sub>R) for ammonia synthesis holds promise for utilizing NO<sub>3</sub><sup>–</sup> pollutants in water under ambient conditions. In the multielectron transfer process of NO<sub>3</sub><sup>–</sup> anions transforming into ammonia, counter-cations play a critical role in influencing the interactions of anions and intermediates. Here, we investigated the impact of Cs<sup>+</sup> ions on the electropolished flat copper (Cu) (100) surface during NO<sub>3</sub>R. Our results show that the presence of Cs<sup>+</sup> leads to a significant decline in Cu activity, with an approximately 8-fold decrease in the partial current density for NH<sub>3</sub> and an increase in interfacial resistance compared to using K<sup>+</sup>. <i>Operando</i> electrochemical Raman spectroscopy revealed the formation of oxygen and hydroxide species adsorbed on the surface (Cu-*O and Cu-*OH, the asterisk symbol indicates surface adsorption), alongside a decrease in the signals of NO<sub>3</sub><sup>–</sup> intermediates in the presence of Cs<sup>+</sup>. Isotope labeling experiments with N<sup>18</sup>O<sub>3</sub><sup>–</sup> identified a key deoxygenation pathway, involving the formation of N<sup>18</sup>O<sub>2</sub> and <sup>18</sup>O species. This deactivated Cu surface, resulting from the accumulation of adsorbed oxygen species, was pronounced under alkaline conditions and was consistently observed on other Cu surface facets, including Cu (111). Density functional theory (DFT) calculations explained how the stabilization of oxygen atoms (*O) on the Cu surface is due to weak hydrogen bonding with hydrated waters of Cs<sup>+</sup> ions, whereas the stronger hydrogen bonding observed with K<sup>+</sup> facilitates oxygen removal. Our findings offer mechanistic insights into the oxygen poisoning of Cu surfaces and highlight the detrimental effects of Cs<sup>+</sup> on NO<sub>3</sub>R.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"16 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144335216","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}
Palladium-catalyzed cross-dehydrogenative coupling (CDC) has prudently advanced the construction of carbon–carbon and C–heteroatom bonds from C–H bonds. In contemporary chemical synthesis, a strong focus on decreased catalyst loading is indispensable, as conventional palladium-catalyzed CDC reactions generally necessitate 10 mol % Pd loading, which is impractical for industrial settings. To tackle this issue, we introduce a new approach utilizing the spatial behavior of phthalazinone-directed highly site-selective arylation through CDC with a minuscule 0.05 mol % of palladium (achieving a TON of >1700) under a light medium. This innovative strategy allows the C–H arylation of various arenes with predictable site-selectivity based on their innate-reactivity pattern. Comprehensive mechanistic studies reveal the roles of ligands, oxidants, visible light, and the distinctive reactivity of the directing group.
{"title":"Spatially Tweaked Amide-Directing Group Enables High-Turnover Pd Catalysts for Site-Selective Remote C–H Arylation","authors":"Chandrasekaran Sivaraj, Thirumanavelan Gandhi, Debabrata Maiti","doi":"10.1021/acscatal.5c02838","DOIUrl":"https://doi.org/10.1021/acscatal.5c02838","url":null,"abstract":"Palladium-catalyzed cross-dehydrogenative coupling (CDC) has prudently advanced the construction of carbon–carbon and C–heteroatom bonds from C–H bonds. In contemporary chemical synthesis, a strong focus on decreased catalyst loading is indispensable, as conventional palladium-catalyzed CDC reactions generally necessitate 10 mol % Pd loading, which is impractical for industrial settings. To tackle this issue, we introduce a new approach utilizing the spatial behavior of phthalazinone-directed highly site-selective arylation through CDC with a minuscule 0.05 mol % of palladium (achieving a TON of >1700) under a light medium. This innovative strategy allows the C–H arylation of various arenes with predictable site-selectivity based on their innate-reactivity pattern. Comprehensive mechanistic studies reveal the roles of ligands, oxidants, visible light, and the distinctive reactivity of the directing group.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"607 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144329312","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 : 2025-06-20DOI: 10.1021/acscatal.4c08027
Mario Urso, Xiaohui Ju, Radhika Nittoor-Veedu, Hyesung Lee, Dagmar Zaoralová, Michal Otyepka, Martin Pumera
The global transition to sustainable energy production revolves around innovations in electrocatalysis, the cornerstone of energy conversion technologies. Over the years, catalysts have evolved from bulk materials to nanoparticles (NPs) and nanoclusters (NCs), culminating in single-atom catalysts (SACs), which represent the peak of catalyst engineering. SACs have revolutionized electrocatalytic processes by maximizing atom efficiency and offering tunable electronic properties, lowering the energy barrier associated with the absorption and desorption of key reaction intermediates, thus promoting specific reaction pathways. This review delves into the synthesis, characterization, and theoretical modeling of SACs, offering a comprehensive analysis of state-of-the-art methodologies. It highlights recent breakthroughs in diverse electrocatalytic reactions, including the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in water splitting, the oxygen reduction reaction (ORR) for Zn–air batteries and fuel cells, the CO2 reduction reaction (CO2RR), and green ammonia synthesis. The discussion emphasizes the unique mechanisms that drive the exceptional performance of SACs, shedding light on their unparalleled activity, selectivity, and stability. By integrating experimental insights with computational advances, this work outlines a path for the rational design of next-generation SACs tailored to a broad spectrum of electrocatalytic applications. While summarizing the current landscape of electrocatalysis by SACs, it also outlines future directions to address the energy challenges of tomorrow, serving as a valuable resource for advancing the field.
{"title":"Single Atom Engineering for Electrocatalysis: Fundamentals and Applications","authors":"Mario Urso, Xiaohui Ju, Radhika Nittoor-Veedu, Hyesung Lee, Dagmar Zaoralová, Michal Otyepka, Martin Pumera","doi":"10.1021/acscatal.4c08027","DOIUrl":"https://doi.org/10.1021/acscatal.4c08027","url":null,"abstract":"The global transition to sustainable energy production revolves around innovations in electrocatalysis, the cornerstone of energy conversion technologies. Over the years, catalysts have evolved from bulk materials to nanoparticles (NPs) and nanoclusters (NCs), culminating in single-atom catalysts (SACs), which represent the peak of catalyst engineering. SACs have revolutionized electrocatalytic processes by maximizing atom efficiency and offering tunable electronic properties, lowering the energy barrier associated with the absorption and desorption of key reaction intermediates, thus promoting specific reaction pathways. This review delves into the synthesis, characterization, and theoretical modeling of SACs, offering a comprehensive analysis of state-of-the-art methodologies. It highlights recent breakthroughs in diverse electrocatalytic reactions, including the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in water splitting, the oxygen reduction reaction (ORR) for Zn–air batteries and fuel cells, the CO<sub>2</sub> reduction reaction (CO<sub>2</sub>RR), and green ammonia synthesis. The discussion emphasizes the unique mechanisms that drive the exceptional performance of SACs, shedding light on their unparalleled activity, selectivity, and stability. By integrating experimental insights with computational advances, this work outlines a path for the rational design of next-generation SACs tailored to a broad spectrum of electrocatalytic applications. While summarizing the current landscape of electrocatalysis by SACs, it also outlines future directions to address the energy challenges of tomorrow, serving as a valuable resource for advancing the field.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"15 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144329351","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 : 2025-06-20DOI: 10.1021/acscatal.5c03259
Qiyuan Wang, Haochuan Jing, Wei Ou, Ying Tao, Yunfei Ma, Taoran Chen, Zhengwu Liao, Jie Wang, Qingzhu Xu, Hongen Cao, Lei Yu, Bin Liu, Chenliang Su
α-Deuterated amines play crucial roles in preparation of deuterated active pharmaceutical ingredients for drug research-and-development (R&D), which requires the development of low-cost, site-selective, and efficient methodologies for their synthesis. D2O is the most ideal and low-cost D-source but generally serves as a “proton pool” to react with the in situ generated carbanion from C=N bonds in prevalent methods that suffer from the poor substrate versatility. Herein, we report a photocatalytic water splitting (PWS) technology for the reductive deuteration of C=N bonds by Au/CdS nanocatalysts. Mechanism insights suggest that incorporating Au nanocatalysts onto CdS semiconductors is important in overcoming the intrinsic poor-photostability of the CdS semiconductor via sulfur fixation and enhancing the photocatalytic performance by improving the separation and migration efficiency of charge carriers. As a result, this PWS-based reductive deuteration strategy using reusable and robust photocatalysts and D2O offers many advantages including mild conditions, site-selectivity, and good substrate versatility in the production of numerous valuable α-deuterated amines, including many deuterated bioactive molecules such as butenafine and enterovirus 71 inhibitors.
{"title":"Photoreductive Deuteration of C=N Bonds by Au/CdS Nanosheets","authors":"Qiyuan Wang, Haochuan Jing, Wei Ou, Ying Tao, Yunfei Ma, Taoran Chen, Zhengwu Liao, Jie Wang, Qingzhu Xu, Hongen Cao, Lei Yu, Bin Liu, Chenliang Su","doi":"10.1021/acscatal.5c03259","DOIUrl":"https://doi.org/10.1021/acscatal.5c03259","url":null,"abstract":"α-Deuterated amines play crucial roles in preparation of deuterated active pharmaceutical ingredients for drug research-and-development (R&D), which requires the development of low-cost, site-selective, and efficient methodologies for their synthesis. D<sub>2</sub>O is the most ideal and low-cost D-source but generally serves as a “proton pool” to react with the <i>in situ</i> generated carbanion from C=N bonds in prevalent methods that suffer from the poor substrate versatility. Herein, we report a photocatalytic water splitting (PWS) technology for the reductive deuteration of C=N bonds by Au/CdS nanocatalysts. Mechanism insights suggest that incorporating Au nanocatalysts onto CdS semiconductors is important in overcoming the intrinsic poor-photostability of the CdS semiconductor via sulfur fixation and enhancing the photocatalytic performance by improving the separation and migration efficiency of charge carriers. As a result, this PWS-based reductive deuteration strategy using reusable and robust photocatalysts and D<sub>2</sub>O offers many advantages including mild conditions, site-selectivity, and good substrate versatility in the production of numerous valuable α-deuterated amines, including many deuterated bioactive molecules such as butenafine and enterovirus 71 inhibitors.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"607 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144329138","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 : 2025-06-20DOI: 10.1021/acscatal.5c01939
Na Lin, Jun-Tao Chen, Yang-Zi Liu, Wei-Ping Deng
A vinylarylcyclopropane (VACP) was synthesized via photocatalysis and employed as a 1,5-all-carbon dipole precursor in palladium-catalyzed [5 + n] cycloadditions with linear (aza)dienes or azomethine imines. This method affords eight- to nine-membered (aza)cycles in yields of up to 95%, displaying exclusive linear regioselectivity and high tolerance toward diverse functional groups. The viability of this synthetic approach was confirmed through scaled-up reactions and subsequent transformations. These findings highlight the significant utility of VACP as a versatile reagent for regioselective cycloaddition reactions.
{"title":"Vinylarylcyclopropanes (VACPs): All-Carbon Dipole Precursors for Controlling Linear Regioselectivity in Cycloaddition Reactions","authors":"Na Lin, Jun-Tao Chen, Yang-Zi Liu, Wei-Ping Deng","doi":"10.1021/acscatal.5c01939","DOIUrl":"https://doi.org/10.1021/acscatal.5c01939","url":null,"abstract":"A vinylarylcyclopropane (VACP) was synthesized via photocatalysis and employed as a 1,5-all-carbon dipole precursor in palladium-catalyzed [5 + <i>n</i>] cycloadditions with linear (aza)dienes or azomethine imines. This method affords eight- to nine-membered (aza)cycles in yields of up to 95%, displaying exclusive linear regioselectivity and high tolerance toward diverse functional groups. The viability of this synthetic approach was confirmed through scaled-up reactions and subsequent transformations. These findings highlight the significant utility of VACP as a versatile reagent for regioselective cycloaddition reactions.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"14 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144329306","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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