Anil Malik, Pankaj Kumar Prajapati, B. Moses Abraham, Sakshi Bhatt, Purashri Basyach and Suman L. Jain
Retraction of ‘Photocatalytic activation and utilization of CO2 for N-formylation of amines promoted by a zinc(II) phthalocyanine grafted on g-carbon nitride hybrid’ by Anil Malik et al., Catal. Sci. Technol., 2022, 12, 2688–2702, https://doi.org/10.1039/D1CY02286E.
{"title":"Retraction: Photocatalytic activation and utilization of CO2 for N-formylation of amines promoted by a zinc(ii) phthalocyanine grafted on g-carbon nitride hybrid","authors":"Anil Malik, Pankaj Kumar Prajapati, B. Moses Abraham, Sakshi Bhatt, Purashri Basyach and Suman L. Jain","doi":"10.1039/D5CY90006A","DOIUrl":"https://doi.org/10.1039/D5CY90006A","url":null,"abstract":"<p >Retraction of ‘Photocatalytic activation and utilization of CO<small><sub>2</sub></small> for <em>N</em>-formylation of amines promoted by a zinc(<small>II</small>) phthalocyanine grafted on g-carbon nitride hybrid’ by Anil Malik <em>et al.</em>, <em>Catal. Sci. Technol.</em>, 2022, <strong>12</strong>, 2688–2702, https://doi.org/10.1039/D1CY02286E.</p>","PeriodicalId":66,"journal":{"name":"Catalysis Science & Technology","volume":" 3","pages":" 947-947"},"PeriodicalIF":4.4,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/cy/d5cy90006a?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143107434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sakshi Bhatt, Ranjita S. Das, Anupama Kumar, Anil Malik, Aishwarya Soni and Suman L. Jain
Retraction of ‘Light-assisted coupling of phenols with CO2 to 2-hydroxybenzaldehydes catalyzed by a g-C3N4/NH2-MIL-101(Fe) composite’ by Sakshi Bhatt et al., Catal. Sci. Technol., 2022, 12, 6805–6818, https://doi.org/10.1039/D2CY01430K.
{"title":"Retraction: Light-assisted coupling of phenols with CO2 to 2-hydroxybenzaldehydes catalyzed by a g-C3N4/NH2-MIL-101(Fe) composite","authors":"Sakshi Bhatt, Ranjita S. Das, Anupama Kumar, Anil Malik, Aishwarya Soni and Suman L. Jain","doi":"10.1039/D5CY90005K","DOIUrl":"https://doi.org/10.1039/D5CY90005K","url":null,"abstract":"<p >Retraction of ‘Light-assisted coupling of phenols with CO<small><sub>2</sub></small> to 2-hydroxybenzaldehydes catalyzed by a g-C<small><sub>3</sub></small>N<small><sub>4</sub></small>/NH<small><sub>2</sub></small>-MIL-101(Fe) composite’ by Sakshi Bhatt <em>et al.</em>, <em>Catal. Sci. Technol.</em>, 2022, <strong>12</strong>, 6805–6818, https://doi.org/10.1039/D2CY01430K.</p>","PeriodicalId":66,"journal":{"name":"Catalysis Science & Technology","volume":" 3","pages":" 946-946"},"PeriodicalIF":4.4,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/cy/d5cy90005k?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143107433","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yongcheng Lan, Jia Wang, Dong Yun, Chungu Xia, Bo Qian and Jianhua Liu
A new class of nitrogen-coordinated Rh heterogeneous catalyst was synthesized by a simple one-pot method for hydroformylation of alkenes with high activity and superior resuability, which could be ascribed to the uniform dispersion of Rh species and enhanced metal–support interactions after the in situ introduction of nitrogen.
{"title":"One-step synthesis of N-coordinated Rh catalysts for efficient and stable alkene hydroformylation†","authors":"Yongcheng Lan, Jia Wang, Dong Yun, Chungu Xia, Bo Qian and Jianhua Liu","doi":"10.1039/D4CY01146E","DOIUrl":"https://doi.org/10.1039/D4CY01146E","url":null,"abstract":"<p >A new class of nitrogen-coordinated Rh heterogeneous catalyst was synthesized by a simple one-pot method for hydroformylation of alkenes with high activity and superior resuability, which could be ascribed to the uniform dispersion of Rh species and enhanced metal–support interactions after the <em>in situ</em> introduction of nitrogen.</p>","PeriodicalId":66,"journal":{"name":"Catalysis Science & Technology","volume":" 3","pages":" 673-677"},"PeriodicalIF":4.4,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143107240","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rahul L Khade, Ronald Daisuke Adukure, Xinyi Zhao, Carolyn Wang, Rudi Fasan, Yong Zhang
Engineered heme proteins possess excellent biocatalytic carbene N-H insertion abilities for sustainable synthesis, and most of them have His as the Fe axial ligand. However, information on the basic reaction mechanisms is limited, and ground states of heme carbenes involved in the prior computational mechanistic studies are under debate. A comprehensive quantum chemical reaction pathway study was performed for the heme model with a His analogue as the axial ligand and carbene from the widely used precursor ethyl diazoacetate with aniline as the substrate. The ground state of this heme carbene was calculated by the high-level complete active space self-consistent field (CASSCF) approach, which shows a closed-shell singlet that is consistent with many experimental works. Based on this, DFT calculations of ten main reaction pathways were compared. Results showed that the most favorable pathway involved the initial formation of the metal-bound ylide, followed by a concerted rearrangement/dissociation transition state to form the free enol, which then underwent a water-assisted proton transfer process to yield the final N-H insertion product. This computational prediction was validated via new experimental data using His-ligated myoglobin variants with different types of carbenes. Overall, this is the first comprehensive computational mechanistic study of heme carbene N-H insertions, particularly for neutral His ligated heme proteins and the first high-level CASSCF confirmation of the ground state of the used heme carbene. The experimental results are also the first in this field. Overall, these results build a solid basis for the proposed reaction mechanism to facilitate future biocatalytic carbene N-H insertion studies.
{"title":"A comprehensive mechanistic investigation of sustainable carbene N-H insertion catalyzed by engineered His-ligated heme proteins.","authors":"Rahul L Khade, Ronald Daisuke Adukure, Xinyi Zhao, Carolyn Wang, Rudi Fasan, Yong Zhang","doi":"10.1039/d4cy00999a","DOIUrl":"10.1039/d4cy00999a","url":null,"abstract":"<p><p>Engineered heme proteins possess excellent biocatalytic carbene N-H insertion abilities for sustainable synthesis, and most of them have His as the Fe axial ligand. However, information on the basic reaction mechanisms is limited, and ground states of heme carbenes involved in the prior computational mechanistic studies are under debate. A comprehensive quantum chemical reaction pathway study was performed for the heme model with a His analogue as the axial ligand and carbene from the widely used precursor ethyl diazoacetate with aniline as the substrate. The ground state of this heme carbene was calculated by the high-level complete active space self-consistent field (CASSCF) approach, which shows a closed-shell singlet that is consistent with many experimental works. Based on this, DFT calculations of ten main reaction pathways were compared. Results showed that the most favorable pathway involved the initial formation of the metal-bound ylide, followed by a concerted rearrangement/dissociation transition state to form the free enol, which then underwent a water-assisted proton transfer process to yield the final N-H insertion product. This computational prediction was validated <i>via</i> new experimental data using His-ligated myoglobin variants with different types of carbenes. Overall, this is the first comprehensive computational mechanistic study of heme carbene N-H insertions, particularly for neutral His ligated heme proteins and the first high-level CASSCF confirmation of the ground state of the used heme carbene. The experimental results are also the first in this field. Overall, these results build a solid basis for the proposed reaction mechanism to facilitate future biocatalytic carbene N-H insertion studies.</p>","PeriodicalId":66,"journal":{"name":"Catalysis Science & Technology","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11771221/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143062606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Monika Mierzejewska, Kamila Łępicka, Jakub Kalecki and Piyush Sindhu Sharma
There is no universal recipe for the proper structure tuning of Ni(OH)2 nanoparticle (NP)-based catalysts for efficient urea electrooxidation (UOR) in alkaline media. However, it is known that fast generation of Ni3+OOH-type catalytic centers that are sustained and resilient during the overall catalytic process is crucial. Towards this, we report how we optimized and compared operating conditions and structural tuning of poly[NP-Ni(OH)2SaltMe] and poly[meso-NP-Ni(OH)2SaldMe] electrocatalysts active in alkaline media towards UOR. We started with studies of morphological differences evoked by the use of different NaOHaq concentrations for catalyst fabrication by SEM and TEM. Then, we distinguished the most promising molecular structures of fabricated catalysts featuring the highest poisoning resistance and in situ generation of poly(NP-Ni3+OOHsalen) electrocatalytic centers for UOR. Furthermore, we found the best conditions for operation of both structured UOR catalysts using a comprehensive electrochemical approach. This approach involved multiple scan rate, Tafel slope, and activation energy (Eac) analysis to finally compare which structured poly[NP-Ni(OH)2salen] catalyst produces catalytic current more efficiently in response to a change in applied potential. Ultimately, we performed a longevity/durability test under real-system mimicking conditions. The fabricated catalysts constituted good platforms for studying the surface-remaining and bulk-remaining types of catalytically active sites of poly[NP-Ni(OH)2salen]s for UOR activity. Our findings point to the bulk-structure-reactivity requirements of poly[NP-Ni(OH)2salen]s, emphasizing their catalytic durability and effectiveness.
{"title":"Tailoring of poly[Ni(OH)2salen] nanoparticle-based electrocatalysts for effective urea remediation†","authors":"Monika Mierzejewska, Kamila Łępicka, Jakub Kalecki and Piyush Sindhu Sharma","doi":"10.1039/D4CY01139B","DOIUrl":"https://doi.org/10.1039/D4CY01139B","url":null,"abstract":"<p >There is no universal recipe for the proper structure tuning of Ni(OH)<small><sub>2</sub></small> nanoparticle (NP)-based catalysts for efficient urea electrooxidation (UOR) in alkaline media. However, it is known that fast generation of Ni<small><sup>3+</sup></small>OOH-type catalytic centers that are sustained and resilient during the overall catalytic process is crucial. Towards this, we report how we optimized and compared operating conditions and structural tuning of poly[NP-Ni(OH)<small><sub>2</sub></small>SaltMe] and poly[<em>meso</em>-NP-Ni(OH)<small><sub>2</sub></small>SaldMe] electrocatalysts active in alkaline media towards UOR. We started with studies of morphological differences evoked by the use of different NaOH<small><sub>aq</sub></small> concentrations for catalyst fabrication by SEM and TEM. Then, we distinguished the most promising molecular structures of fabricated catalysts featuring the highest poisoning resistance and <em>in situ</em> generation of poly(NP-Ni<small><sup>3+</sup></small>OOHsalen) electrocatalytic centers for UOR. Furthermore, we found the best conditions for operation of both structured UOR catalysts using a comprehensive electrochemical approach. This approach involved multiple scan rate, Tafel slope, and activation energy (<em>E</em><small><sub>ac</sub></small>) analysis to finally compare which structured poly[NP-Ni(OH)<small><sub>2</sub></small>salen] catalyst produces catalytic current more efficiently in response to a change in applied potential. Ultimately, we performed a longevity/durability test under real-system mimicking conditions. The fabricated catalysts constituted good platforms for studying the surface-remaining and bulk-remaining types of catalytically active sites of poly[NP-Ni(OH)<small><sub>2</sub></small>salen]s for UOR activity. Our findings point to the bulk-structure-reactivity requirements of poly[NP-Ni(OH)<small><sub>2</sub></small>salen]s, emphasizing their catalytic durability and effectiveness.</p>","PeriodicalId":66,"journal":{"name":"Catalysis Science & Technology","volume":" 3","pages":" 794-807"},"PeriodicalIF":4.4,"publicationDate":"2025-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/cy/d4cy01139b?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143107231","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Adrian Hühn, Tao Jiang, Manuel Corral Valero, Mickaël Rivallan, Anne Lesage, Carine Michel and Pascal Raybaud
The chemical nature of adsorbed inorganic additives such as phophates used in the preparation of heterogeneous catalysts is suspected to impact their resulting activity. Predominant phosphate species located on the surfaces of the γ-alumina catalytic support are identified by using one-dimensional 31P NMR spectra as the only experimental input. The detailed insight is made possible by combining machine learning (ML) 31P chemical shift prediction and ab initio molecular dynamics (AIMD) to sample conformers of 10 representative possible structures and generate theoretical spectra, which were then used to decompose mathematically the broad experimental peak. At low P concentration, several types of monomeric species are found to co-exist on the γ-alumina (110) facets. Increasing the P concentration yields a marked increase in one monomeric species and one dimeric species both located on the (110) facets, whereas phosphates are mainly absent from the (100) facet. The NMR spectra broadening is interpreted by two levels of structural disorders: the various types of P species and the conformational distribution of each species. We finally propose some implications for the catalytic properties.
{"title":"The speciation of phosphates adsorbed on γ-alumina revealed by 31P NMR, AIMD and machine learning†","authors":"Adrian Hühn, Tao Jiang, Manuel Corral Valero, Mickaël Rivallan, Anne Lesage, Carine Michel and Pascal Raybaud","doi":"10.1039/D4CY01152J","DOIUrl":"https://doi.org/10.1039/D4CY01152J","url":null,"abstract":"<p >The chemical nature of adsorbed inorganic additives such as phophates used in the preparation of heterogeneous catalysts is suspected to impact their resulting activity. Predominant phosphate species located on the surfaces of the γ-alumina catalytic support are identified by using one-dimensional <small><sup>31</sup></small>P NMR spectra as the only experimental input. The detailed insight is made possible by combining machine learning (ML) <small><sup>31</sup></small>P chemical shift prediction and <em>ab initio</em> molecular dynamics (AIMD) to sample conformers of 10 representative possible structures and generate theoretical spectra, which were then used to decompose mathematically the broad experimental peak. At low P concentration, several types of monomeric species are found to co-exist on the γ-alumina (110) facets. Increasing the P concentration yields a marked increase in one monomeric species and one dimeric species both located on the (110) facets, whereas phosphates are mainly absent from the (100) facet. The NMR spectra broadening is interpreted by two levels of structural disorders: the various types of P species and the conformational distribution of each species. We finally propose some implications for the catalytic properties.</p>","PeriodicalId":66,"journal":{"name":"Catalysis Science & Technology","volume":" 3","pages":" 878-884"},"PeriodicalIF":4.4,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143107427","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xing Tan, Ruixing Du, Qitong Zhong, Longfei Liao, Huanhao Chen, Zhenchen Tang, Dafeng Yan, Shiming Chen and Feng Zeng
Replacing the sluggish oxygen evolution reaction with ethanol oxidation can reduce the overpotential while generating value-added products. In this study, a highly active and stable catalyst was synthesized via electrochemical deposition, enabling the leaching of Ni and co-deposition of Au and Ni to form an Au–Ni alloy on Ni foam. The Au–Ni synergy enhances ethanol adsorption, tailors surface oxygen species, and shortens the distance between reaction intermediates, driving ethanol oxidation to acetate at low potentials and favoring acetaldehyde formation at higher potentials. The resulting electrode achieves 163 mA cm−2 at 1.57 V vs. RHE and 209 mA cm−2 at 1.90 V vs. RHE with excellent stability, offering a cost-effective alternative for the anode reaction in hydrogen production.
{"title":"Au–Ni synergy for enhanced electrochemical oxidation of ethanol over Au/Ni foam electrode†","authors":"Xing Tan, Ruixing Du, Qitong Zhong, Longfei Liao, Huanhao Chen, Zhenchen Tang, Dafeng Yan, Shiming Chen and Feng Zeng","doi":"10.1039/D4CY01490A","DOIUrl":"https://doi.org/10.1039/D4CY01490A","url":null,"abstract":"<p >Replacing the sluggish oxygen evolution reaction with ethanol oxidation can reduce the overpotential while generating value-added products. In this study, a highly active and stable catalyst was synthesized <em>via</em> electrochemical deposition, enabling the leaching of Ni and co-deposition of Au and Ni to form an Au–Ni alloy on Ni foam. The Au–Ni synergy enhances ethanol adsorption, tailors surface oxygen species, and shortens the distance between reaction intermediates, driving ethanol oxidation to acetate at low potentials and favoring acetaldehyde formation at higher potentials. The resulting electrode achieves 163 mA cm<small><sup>−2</sup></small> at 1.57 V <em>vs.</em> RHE and 209 mA cm<small><sup>−2</sup></small> at 1.90 V <em>vs.</em> RHE with excellent stability, offering a cost-effective alternative for the anode reaction in hydrogen production.</p>","PeriodicalId":66,"journal":{"name":"Catalysis Science & Technology","volume":" 3","pages":" 933-945"},"PeriodicalIF":4.4,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143107432","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Maria Matveeva, Bartosz Trzaskowski and Anna Kajetanowicz
One of the main drawbacks of stereoretentive ruthenium catalysts that allow the synthesis of olefins with a defined double bond geometry is their limited stability in the presence of oxygen. To remove the bottleneck that inhibits their widespread use, we prepared a series of Hoveyda–Grubbs-type complexes with a modified ether moiety in the benzylidene substituent. The yields obtained in air remain lower than those obtained under an inert atmosphere. Unexpectedly, however, O-benzyl catalyst Ru14b typically led to better yields with high selectivities compared to the benchmark OiPr catalyst Ru4. A parallel DFT study confirmed that the four-coordinate Ru(IV)-oxo product reported earlier by Fogg results from the oxygen attack on the Ru–C bond and the elimination of aldehyde from a metalladioxetane-like transition state.
{"title":"Modifications of substituents on the chelating oxygen atom in stereoretentive Hoveyda–Grubbs-type complexes and their influence on catalytic properties†","authors":"Maria Matveeva, Bartosz Trzaskowski and Anna Kajetanowicz","doi":"10.1039/D4CY01357C","DOIUrl":"https://doi.org/10.1039/D4CY01357C","url":null,"abstract":"<p >One of the main drawbacks of stereoretentive ruthenium catalysts that allow the synthesis of olefins with a defined double bond geometry is their limited stability in the presence of oxygen. To remove the bottleneck that inhibits their widespread use, we prepared a series of Hoveyda–Grubbs-type complexes with a modified ether moiety in the benzylidene substituent. The yields obtained in air remain lower than those obtained under an inert atmosphere. Unexpectedly, however, <em>O</em>-benzyl catalyst <strong>Ru14b</strong> typically led to better yields with high selectivities compared to the benchmark O<em>i</em>Pr catalyst <strong>Ru4</strong>. A parallel DFT study confirmed that the four-coordinate Ru(<small>IV</small>)-oxo product reported earlier by Fogg results from the oxygen attack on the Ru–C bond and the elimination of aldehyde from a metalladioxetane-like transition state.</p>","PeriodicalId":66,"journal":{"name":"Catalysis Science & Technology","volume":" 3","pages":" 783-793"},"PeriodicalIF":4.4,"publicationDate":"2025-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143107230","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhihao Wei, Bin Guan, Zhongqi Zhuang, Junyan Chen, Lei Zhu, Zeren Ma, Xuehan Hu, Chenyu Zhu, Sikai Zhao, Kaiyou Shu, Hongtao Dang, Tiankui Zhu and Zhen Huang
Selective catalytic reduction (SCR) technology is one of the main measures to achieve the pollutant emission reduction target of diesel engines, and the NH3-SCR exhaust gas aftertreatment technology systems used at present are all based on the design scheme using liquid urea aqueous solution as a reducing agent. However, the SCR system using urea aqueous solution as the reducing agent has some problems in the process of use, such as freezing of the reducing agent (−11 °C) resulting in blocking of the reducing agent transport pipeline; incomplete hydrolysis of urea aqueous solution will not only form crystallization in the pipeline, but also lead to a certain error between the amount of urea injection and the amount of ammonia (urea pyrolysis and hydrolysis to produce ammonia), which affects the conversion efficiency of SCR system. The effective ammonia content per unit volume of urea aqueous solution is low (17.3%), and urea aqueous solution needs to be supplemented at 1500–2500 km, which is not conducive to the quality control of urea aqueous solution, and it is difficult to ensure the consistency of nitrogen oxide (NOx) conversion effect in the SCR system. Because there are many insurmountable defects in urea SCR technology, researchers at home and abroad have turned their research focus to SSCR (solid SCR) technology. Solid selective catalytic reduction (SSCR) technology utilizes solid ammonia storage, releasing ammonia gas directly upon heating. This approach offers significant advantages over urea-based SCR, addressing its inherent limitations. This paper provides an overview of SCR and SSCR technologies, discusses the formation of nitrogen oxides, the NH3-SCR mechanism, and the principles of operation for both urea SCR and solid ammonia storage materials. It also explores the development of SSCR systems, highlighting their potential to overcome the challenges faced by conventional SCR methods.
{"title":"Review on solid selective catalytic reduction (SSCR) technology: excellent optimization of selective catalytic reduction technology","authors":"Zhihao Wei, Bin Guan, Zhongqi Zhuang, Junyan Chen, Lei Zhu, Zeren Ma, Xuehan Hu, Chenyu Zhu, Sikai Zhao, Kaiyou Shu, Hongtao Dang, Tiankui Zhu and Zhen Huang","doi":"10.1039/D4CY01045K","DOIUrl":"https://doi.org/10.1039/D4CY01045K","url":null,"abstract":"<p >Selective catalytic reduction (SCR) technology is one of the main measures to achieve the pollutant emission reduction target of diesel engines, and the NH<small><sub>3</sub></small>-SCR exhaust gas aftertreatment technology systems used at present are all based on the design scheme using liquid urea aqueous solution as a reducing agent. However, the SCR system using urea aqueous solution as the reducing agent has some problems in the process of use, such as freezing of the reducing agent (−11 °C) resulting in blocking of the reducing agent transport pipeline; incomplete hydrolysis of urea aqueous solution will not only form crystallization in the pipeline, but also lead to a certain error between the amount of urea injection and the amount of ammonia (urea pyrolysis and hydrolysis to produce ammonia), which affects the conversion efficiency of SCR system. The effective ammonia content per unit volume of urea aqueous solution is low (17.3%), and urea aqueous solution needs to be supplemented at 1500–2500 km, which is not conducive to the quality control of urea aqueous solution, and it is difficult to ensure the consistency of nitrogen oxide (NOx) conversion effect in the SCR system. Because there are many insurmountable defects in urea SCR technology, researchers at home and abroad have turned their research focus to SSCR (solid SCR) technology. Solid selective catalytic reduction (SSCR) technology utilizes solid ammonia storage, releasing ammonia gas directly upon heating. This approach offers significant advantages over urea-based SCR, addressing its inherent limitations. This paper provides an overview of SCR and SSCR technologies, discusses the formation of nitrogen oxides, the NH<small><sub>3</sub></small>-SCR mechanism, and the principles of operation for both urea SCR and solid ammonia storage materials. It also explores the development of SSCR systems, highlighting their potential to overcome the challenges faced by conventional SCR methods.</p>","PeriodicalId":66,"journal":{"name":"Catalysis Science & Technology","volume":" 3","pages":" 647-668"},"PeriodicalIF":4.4,"publicationDate":"2025-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143107234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hyo-Jin Kim, Kohsuke Mori, Takayoshi Nakano and Hiromi Yamashita
A design framework for metal 3D-printed self-catalytic reactors (3D SCRs) using stainless steel (STS) has been demonstrated. The surface functionalization of STS was achieved through a two-step dealloying process, which is first optimized on metal powder precursor, and then successfully extended to STS 3D SCRs as a practical active catalyst for CO2 methanation.
{"title":"Rational design of stainless steel self-catalytic reactors for CO2 methanation: extending from metal powder to 3D-printed reactors†","authors":"Hyo-Jin Kim, Kohsuke Mori, Takayoshi Nakano and Hiromi Yamashita","doi":"10.1039/D4CY01244E","DOIUrl":"https://doi.org/10.1039/D4CY01244E","url":null,"abstract":"<p >A design framework for metal 3D-printed self-catalytic reactors (3D SCRs) using stainless steel (STS) has been demonstrated. The surface functionalization of STS was achieved through a two-step dealloying process, which is first optimized on metal powder precursor, and then successfully extended to STS 3D SCRs as a practical active catalyst for CO<small><sub>2</sub></small> methanation.</p>","PeriodicalId":66,"journal":{"name":"Catalysis Science & Technology","volume":" 3","pages":" 669-672"},"PeriodicalIF":4.4,"publicationDate":"2025-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/cy/d4cy01244e?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143107239","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}