Pub Date : 2026-03-15DOI: 10.1016/j.jcat.2026.116800
You Wang, Shiyuan Wei, Yiwen Cao, Jiawei Li, Jianhan Huang
The development of highly efficient catalysts for the conversion of CO2 into high-value-added chemicals has emerged as a research hotspot of great significance and technical challenge in the field of green synthesis. Cu2O nanoparticles serve as low-cost, abundant and versatile nanocatalysts widely applied in diverse catalytic transformations, while the facile construction of ultrafine Cu2O nanoparticles with exceptional catalytic activity remains a great challenge. In this work, according to hydroxyl engineering strategy on functionalized covalent organic frameworks (COFs), we reported the successful fabrication of uniformly dispersed ultrafine Cu2O nanoparticles (<3 nm) on functionalized COFs for CO2 conversion. The regulation of hydroxyl group (–OH) numbers on pore walls of the COFs can precisely control the confined growth of Cu2O nanoparticles with different particle size ranging from 17.2 nm to 2.4 nm, and the DTA-COFs substrate containing two –OH can cooperate with the ultrafine Cu2O (2.4 nm) to significantly improve their adsorption and activation of CO2 and propargylamine. The resulting Cu2O@DTA-COFs nanocatalysts exhibited remarkable catalytic efficiency in the cyclization of propargylamine and CO2 under mild condition, with a high yield of 99% and an impressive turnover frequency of 100.3 h−1. Moreover, even in simulated flue gas with diluted CO2, the produced nanocatalysts still maintained exceptional catalytic activity (55% at 1 h and 94% at 2 h). The present work provides a novel approach for developing ultrafine Cu2O-based nanocatalysts through hydroxyl engineering strategy on functionalized COFs, which serves as highly efficient non-noble-metal catalysts for CO2 conversion
{"title":"Ultrafine Cu2O nanoparticles through hydroxyl engineering strategy on functionalized covalent organic frameworks for efficient CO2 conversion","authors":"You Wang, Shiyuan Wei, Yiwen Cao, Jiawei Li, Jianhan Huang","doi":"10.1016/j.jcat.2026.116800","DOIUrl":"https://doi.org/10.1016/j.jcat.2026.116800","url":null,"abstract":"The development of highly efficient catalysts for the conversion of CO<sub>2</sub> into high-value-added chemicals has emerged as a research hotspot of great significance and technical challenge in the field of green synthesis. Cu<sub>2</sub>O nanoparticles serve as low-cost, abundant and versatile nanocatalysts widely applied in diverse catalytic transformations, while the facile construction of ultrafine Cu<sub>2</sub>O nanoparticles with exceptional catalytic activity remains a great challenge. In this work, according to hydroxyl engineering strategy on functionalized covalent organic frameworks (COFs), we reported the successful fabrication of uniformly dispersed ultrafine Cu<sub>2</sub>O nanoparticles (<3 nm) on functionalized COFs for CO<sub>2</sub> conversion. The regulation of hydroxyl group (–OH) numbers on pore walls of the COFs can precisely control the confined growth of Cu<sub>2</sub>O nanoparticles with different particle size ranging from 17.2 nm to 2.4 nm, and the DTA-COFs substrate containing two –OH can cooperate with the ultrafine Cu<sub>2</sub>O (2.4 nm) to significantly improve their adsorption and activation of CO<sub>2</sub> and propargylamine. The resulting Cu<sub>2</sub>O@DTA-COFs nanocatalysts exhibited remarkable catalytic efficiency in the cyclization of propargylamine and CO<sub>2</sub> under mild condition, with a high yield of 99% and an impressive turnover frequency of 100.3 h<sup>−1</sup>. Moreover, even in simulated flue gas with diluted CO<sub>2</sub>, the produced nanocatalysts still maintained exceptional catalytic activity (55% at 1 h and 94% at 2 h). The present work provides a novel approach for developing ultrafine Cu<sub>2</sub>O-based nanocatalysts through hydroxyl engineering strategy on functionalized COFs, which serves as highly efficient non-noble-metal catalysts for CO<sub>2</sub> conversion","PeriodicalId":346,"journal":{"name":"Journal of Catalysis","volume":"412 1","pages":""},"PeriodicalIF":7.3,"publicationDate":"2026-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147461997","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 : 2026-03-12DOI: 10.1016/j.jcat.2026.116822
Ankit Kachore, Varun Aggarwal, Ekta Bala, Hemant Singh, Manickam Selvaraj, Mohammed A. Assiri, , Rakesh Kumar, Praveen Kumar Verma
Ligand exchange strategy in relay catalysis has emerged as a powerful tool, enabling seamless adaptation of multiple catalytic cycles through dynamic exchange of ligands. This study presents strategic convergence of two traditionally distinct paradigms in catalysis via coordination of dual-ligand/single-metal and dual-metal/single-ligand systems. The synergistic potential of these frameworks under a unified ligand exchange enabled relay catalysis approach revealed temporal and spatial control over ligand–metal coordination to unlock novel reactivity profiles and enhance catalytic efficiencies. Mechanistic investigations, including kinetic, and computational studies, illuminate the intricate relay events that govern catalyst evolution during turnover. These studies highlighted how ligand identity and exchange rates modulate transition state energies, guide selective substrate activation, and influence relay fidelity. Importantly, controlled relay mechanisms can enable insitu catalyst speciation and functional group compatibility in complex reaction networks. The unification of dual-ligand/single-metal and dual-metal/single-ligand strategies via ligand exchange relay catalysis paves the way for innovative transformations across a spectrum of synthetic challenges. Applications range from alkylation, arylation and cross-coupling to asymmetric catalysis and small-molecule functionalizations. By linking the fields of coordination and organometallic chemistry, this work achieves more than just a conceptual connection and represents ligand exchange relay catalysis as a customizable and controllable method for designing next generation catalysts.
{"title":"Strategic convergence in ligand exchange relay catalysis: unifying coordination of ’dual-ligand/single-metal’ and ’dual-metal/single-ligand’ paradigms in advanced catalysis","authors":"Ankit Kachore, Varun Aggarwal, Ekta Bala, Hemant Singh, Manickam Selvaraj, Mohammed A. Assiri, , Rakesh Kumar, Praveen Kumar Verma","doi":"10.1016/j.jcat.2026.116822","DOIUrl":"https://doi.org/10.1016/j.jcat.2026.116822","url":null,"abstract":"Ligand exchange strategy in relay catalysis has emerged as a powerful tool, enabling seamless adaptation of multiple catalytic cycles through dynamic exchange of ligands. This study presents strategic convergence of two traditionally distinct paradigms in catalysis via coordination of dual-ligand/single-metal and dual-metal/single-ligand systems. The synergistic potential of these frameworks under a unified ligand exchange enabled relay catalysis approach revealed temporal and spatial control over ligand–metal coordination to unlock novel reactivity profiles and enhance catalytic efficiencies. Mechanistic investigations, including kinetic, and computational studies, illuminate the intricate relay events that govern catalyst evolution during turnover. These studies highlighted how ligand identity and exchange rates modulate transition state energies, guide selective substrate activation, and influence relay fidelity. Importantly, controlled relay mechanisms can enable insitu catalyst speciation and functional group compatibility in complex reaction networks. The unification of dual-ligand/single-metal and dual-metal/single-ligand strategies via ligand exchange relay catalysis paves the way for innovative transformations across a spectrum of synthetic challenges. Applications range from alkylation, arylation and cross-coupling to asymmetric catalysis and small-molecule functionalizations. By linking the fields of coordination and organometallic chemistry, this work achieves more than just a conceptual connection and represents ligand exchange relay catalysis as a customizable and controllable method for designing next generation catalysts.","PeriodicalId":346,"journal":{"name":"Journal of Catalysis","volume":"54 1","pages":""},"PeriodicalIF":7.3,"publicationDate":"2026-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147440442","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 : 2026-03-12DOI: 10.1016/j.jcat.2026.116814
Long-Gen Hu, Guo-Sheng Zhang, Chen Chen, Pei-Ying Peng, Yong Lu, Xiao-Li Zhao, Ying-Xi Hua, Ye Liu
Hydrocarboxylation of alkynes using formic acid (FA) as carboxyl-source is highly challenging due to the competing decomposition of FA to H2/CO2 and to CO/H2O to sacrifice the utilization efficiency of FA as well as to induce the side-reactions. Herein, a series of flexible and steric-bulky bis-P,O-ligands (L1-L4) were synthesized and characterized on purpose to promote this reaction by avoiding unwanted FA-decomposition. It was found that L2, characteristic with the most electron-rich nature, the bulkiest steric-hindrance, and the convenient P,P-chelation effect, enabled Pd(TFA)2 highly active and selective for hydrocarboxylation of alkynes with FA under additive-free condition, affording the target α,β-unsaturated branched-carboxylic acids in the yield of 37–85 %. The in situ FT-IR analysis verified that the competing decomposition of FA like dehydrogenation to H2/CO2 and dehydration to CO/H2O were completely inhibited, and the labile FA-based hybrid anhydride was the real product generated upon the catalysis of L2-modifed Pd(TFA)2 system.
以甲酸为羧基源的炔烃羟基化反应具有很大的挑战性，因为甲酸会竞争性地分解为H2/CO2和CO/H2O，从而牺牲甲酸的利用效率并诱发副反应。本文合成了一系列具有柔性和立体体积的双- p， o -配体（L1-L4），并对其进行了表征，以避免不必要的fa分解，从而促进该反应。结果表明，L2具有最富电子的性质，最大的空间位阻和方便的P，P螯合作用，使Pd(TFA)2在无添加剂的条件下具有高活性和选择性，可以与FA进行烷基羟基化反应，得到产率为37 - 85%的α，β-不饱和支链羧酸。原位FT-IR分析证实，脱氢制H2/CO2和脱水制CO/H2O等FA的竞争分解被完全抑制，在l2修饰Pd(TFA)2体系的催化下，生成的是不稳定的FA基杂化酸酐。
{"title":"Advances for synthesis of bis-P,O-ligands and their stereo-electronic effect on Pd-catalyzed hydrocarboxylation of alkynes with formic acid without void decomposition","authors":"Long-Gen Hu, Guo-Sheng Zhang, Chen Chen, Pei-Ying Peng, Yong Lu, Xiao-Li Zhao, Ying-Xi Hua, Ye Liu","doi":"10.1016/j.jcat.2026.116814","DOIUrl":"https://doi.org/10.1016/j.jcat.2026.116814","url":null,"abstract":"Hydrocarboxylation of alkynes using formic acid (FA) as carboxyl-source is highly challenging due to the competing decomposition of FA to H<sub>2</sub>/CO<sub>2</sub> and to CO/H<sub>2</sub>O to sacrifice the utilization efficiency of FA as well as to induce the side-reactions. Herein, a series of flexible and steric-bulky bis-P,O-ligands (<strong>L1-L4</strong>) were synthesized and characterized on purpose to promote this reaction by avoiding unwanted FA-decomposition. It was found that <strong>L2</strong>, characteristic with the most electron-rich nature, the bulkiest steric-hindrance, and the convenient P,P-chelation effect, enabled Pd(TFA)<sub>2</sub> highly active and selective for hydrocarboxylation of alkynes with FA under additive-free condition, affording the target <em>α,β</em>-unsaturated branched-carboxylic acids in the yield of 37–85 %. The <em>in situ</em> FT-IR analysis verified that the competing decomposition of FA like dehydrogenation to H<sub>2</sub>/CO<sub>2</sub> and dehydration to CO/H<sub>2</sub>O were completely inhibited, and the labile FA-based hybrid anhydride was the real product generated upon the catalysis of <strong>L2</strong>-modifed Pd(TFA)<sub>2</sub> system.","PeriodicalId":346,"journal":{"name":"Journal of Catalysis","volume":"84 1","pages":""},"PeriodicalIF":7.3,"publicationDate":"2026-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147440447","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 functionalization of gem-difluoroalkenes provides a modular synthetic method for monofluoroalkenes, yet the competition between β-fluoride elimination and alternative pathways remains a significant challenge in reaction design. Herein, we employ density functional theory (DFT) calculations to elucidate the divergent mechanisms of Pd(II)-catalyzed defluoroarylation and nitrite-enabled chloroarylation (via reductive elimination). Our results demonstrate that Pd(II)-catalyzed processes follow a cationic pathway, in which stereoselectivity is kinetically controlled by β-fluoride elimination, with transition-state energy differences (∼5.0 kcal/mol) arising from steric repulsion and non-covalent interactions within the ligand environment. In contrast, for the chloroarylation of gem-difluorostyrenes, it was found that the traditionally dominant β-fluoride elimination is suppressed by a mechanistic shift to a high-valent Pd(IV) species. Calculations show that C–Cl reductive elimination from a Pd(II) center is kinetically prohibitive (ΔG‡ > 35 kcal/mol), whereas a nitrite-mediated transition to Pd(IV) significantly lowers the barrier (ΔG‡ ≈ 11–19 kcal/mol), enabling regioselective difunctionalization while preserving the fluorine atoms. These findings provide a predictive framework for modulating palladium valence states to achieve divergent reactivity in fluorinated alkene synthesis.
{"title":"Tuning palladium valence states for divergent reactivity: computational study of β-fluoride elimination vs. high-valent reductive elimination","authors":"Chenxi Li, Ruoxi Liu, Junfeng Qian, Zhihui Zhang, Qun Chen, Yihan Tang","doi":"10.1016/j.jcat.2026.116801","DOIUrl":"https://doi.org/10.1016/j.jcat.2026.116801","url":null,"abstract":"Palladium-catalyzed functionalization of <em>gem</em>-difluoroalkenes provides a modular synthetic method for monofluoroalkenes, yet the competition between <em>β</em>-fluoride elimination and alternative pathways remains a significant challenge in reaction design. Herein, we employ density functional theory (DFT) calculations to elucidate the divergent mechanisms of Pd(II)-catalyzed defluoroarylation and nitrite-enabled chloroarylation (<em>via</em> reductive elimination). Our results demonstrate that Pd(II)-catalyzed processes follow a cationic pathway, in which stereoselectivity is kinetically controlled by <em>β</em>-fluoride elimination, with transition-state energy differences (∼5.0 kcal/mol) arising from steric repulsion and non-covalent interactions within the ligand environment. In contrast, for the chloroarylation of <em>gem</em>-difluorostyrenes, it was found that the traditionally dominant <em>β</em>-fluoride elimination is suppressed by a mechanistic shift to a high-valent Pd(IV) species. Calculations show that C–Cl reductive elimination from a Pd(II) center is kinetically prohibitive (ΔG<sup>‡</sup> > 35 kcal/mol), whereas a nitrite-mediated transition to Pd(IV) significantly lowers the barrier (ΔG<sup>‡</sup> ≈ 11–19 kcal/mol), enabling regioselective difunctionalization while preserving the fluorine atoms. These findings provide a predictive framework for modulating palladium valence states to achieve divergent reactivity in fluorinated alkene synthesis.","PeriodicalId":346,"journal":{"name":"Journal of Catalysis","volume":"31 1","pages":""},"PeriodicalIF":7.3,"publicationDate":"2026-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147383974","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}
Perfluorosulfonic acid ionomer, known as Nafion, has been frequently employed as a binder in electrode fabrication for electrocatalytic reduction of carbon dioxide, owing to its exceptional ionic conductivity and chemical robustness. However, the effect of Nafion on the catalytic interface hence the activity has been largely overlooked. Herein, we employ a Nafion-modified copper electrode for the electroreduction of carbon dioxide. The presence of Nafion with optimal amount surprisingly improves the selectivity of C1 products, with a Faradaic efficiency of >80% at a current density of −50 mA cm−2, comparing to a Faradaic efficiency of only 52% for C1 products on a pristine copper. We reveal that the hydrophobic PTFE backbone in Nafion promotes the formation of HCOO–, while the −SO3H group is beneficial to the formation of CO. Employing in situ Raman spectroscopy, we reveal that Nafion alters the binding configuration of *CO intermediate and reduces *CO coverage on copper surface. Moreover, Nafion layer is found to reduce the availability of water molecules at the interface, impeding proton transfer and hindering C–C coupling process. Additionally, the tuning between C1 molecules, i.e. the ratio between CO vs. HCOO–, is successfully achieved by adjusting the thickness of the copper catalyst and the maximum Faradaic efficiency of C1 products reaches 85.5 %. This study underscores the unneglectable effect of Nafion on catalytic activity of copper electrode.
由于其优异的离子导电性和化学稳定性，被称为Nafion的全氟磺酸离聚体经常被用作电极制造中用于电催化还原二氧化碳的粘合剂。然而，Nafion对催化界面的影响在很大程度上被忽视了。在这里，我们采用了一种nafion修饰的铜电极来电还原二氧化碳。最优用量的Nafion的存在令人惊讶地提高了C1产物的选择性，在电流密度为- 50 mA cm - 2时，其法拉第效率为>；80%，而在原始铜上，C1产物的法拉第效率仅为52%。我们发现Nafion中的疏水性聚四氟乙烯主链促进了HCOO -的形成，而−SO3H基团有利于CO的形成。利用原位拉曼光谱，我们发现Nafion改变了*CO中间体的结合构型，降低了*CO在铜表面的覆盖率。此外，发现Nafion层降低了界面处水分子的可用性，阻碍了质子转移和C-C耦合过程。此外，通过调整铜催化剂的厚度，成功地实现了C1分子之间的调节，即CO与HCOO -的比例，C1产物的最高法拉第效率达到85.5%。本研究强调了钠离子对铜电极催化活性的不可忽视的影响。
{"title":"Elucidating the mechanism of Nafion-mediated selectivity towards single-carbon products in electroreduction of carbon dioxide on copper","authors":"Hexing Yang, Chunjing Ran, Chenglong Wang, Wangjiang Gao, Shengzhou Xu, Dan Ren","doi":"10.1016/j.jcat.2026.116809","DOIUrl":"https://doi.org/10.1016/j.jcat.2026.116809","url":null,"abstract":"Perfluorosulfonic acid ionomer, known as Nafion, has been frequently employed as a binder in electrode fabrication for electrocatalytic reduction of carbon dioxide, owing to its exceptional ionic conductivity and chemical robustness. However, the effect of Nafion on the catalytic interface hence the activity has been largely overlooked. Herein, we employ a Nafion-modified copper electrode for the electroreduction of carbon dioxide. The presence of Nafion with optimal amount surprisingly improves the selectivity of C<sub>1</sub> products, with a Faradaic efficiency of >80% at a current density of −50 mA cm<sup>−2</sup>, comparing to a Faradaic efficiency of only 52% for C<sub>1</sub> products on a pristine copper. We reveal that the hydrophobic PTFE backbone in Nafion promotes the formation of HCOO<sup>–</sup>, while the −SO<sub>3</sub>H group is beneficial to the formation of CO. Employing <em>in situ</em> Raman spectroscopy, we reveal that Nafion alters the binding configuration of *CO intermediate and reduces *CO coverage on copper surface. Moreover, Nafion layer is found to reduce the availability of water molecules at the interface, impeding proton transfer and hindering C–C coupling process. Additionally, the tuning between C<sub>1</sub> molecules, i.e. the ratio between CO vs. HCOO<sup>–</sup>, is successfully achieved by adjusting the thickness of the copper catalyst and the maximum Faradaic efficiency of C<sub>1</sub> products reaches 85.5 %. This study underscores the unneglectable effect of Nafion on catalytic activity of copper electrode.","PeriodicalId":346,"journal":{"name":"Journal of Catalysis","volume":"71 1","pages":""},"PeriodicalIF":7.3,"publicationDate":"2026-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147383971","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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