Pub Date : 2024-12-23DOI: 10.1021/acscatal.4c06676
Ikuya Fujii, Kazuhiko Semba, Yoshiaki Nakao
We report the site-selective C–F magnesiation of multifluorinated arenes catalyzed by Rh–Al bimetallic complexes to prepare synthetically important fluorine-containing organomagnesium reagents. We clarified that the catalyst-control site-selectivity stems from the steric and electronic environments of the substrates. The protocol can be applied to the efficient synthesis of fluorine-containing pharmaceuticals and liquid crystal molecules.
{"title":"Site-Selective Magnesiation of Multifluorinated Arenes Catalyzed by Rhodium–Aluminum Bimetallic Complexes","authors":"Ikuya Fujii, Kazuhiko Semba, Yoshiaki Nakao","doi":"10.1021/acscatal.4c06676","DOIUrl":"https://doi.org/10.1021/acscatal.4c06676","url":null,"abstract":"We report the site-selective C–F magnesiation of multifluorinated arenes catalyzed by Rh–Al bimetallic complexes to prepare synthetically important fluorine-containing organomagnesium reagents. We clarified that the catalyst-control site-selectivity stems from the steric and electronic environments of the substrates. The protocol can be applied to the efficient synthesis of fluorine-containing pharmaceuticals and liquid crystal molecules.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"2 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142873850","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 : 2024-12-23DOI: 10.1021/acscatal.4c04190
Raghuram Gaddam, Zirui Wang, Yichen Li, Lauren C. Harris, Michael A. Pence, Efren R. Guerrero, Paul J. A. Kenis, Andrew A. Gewirth, Joaquín Rodríguez-López
Automated, rapid electrocatalyst discovery techniques that comprehensively address the exploration of chemical spaces, characterization of catalyst robustness, reproducibility, and translation of results to (flow) electrolysis operation are needed. Responding to the growing interest in biomass valorization, we studied the glycerol electro-oxidation reaction (GEOR) on gold in alkaline media as a model reaction to demonstrate the efficacy of such methodology introduced here. Our platform combines individually addressable electrode arrays with HardPotato, a Python application programming interface for potentiostat control, to automate electrochemical experiments and data analysis operations. We systematically investigated the effects of reduction potential (El) and pulse width (PW) on GEOR activity during the electrodeposition (Edep) of gold, evaluating 28 different conditions in triplicate measurements with great versatility. Our findings reveal a direct correlation between El and GEOR activity. Upon CV cycling, we recorded a 52% increase in peak current density and a −0.25 V shift in peak potential as El varied from −0.2 to −1.4 V. We also identified an optimal PW of ∼1.0 s, yielding maximum catalytic performance. The swift analysis enabled by our methodology allowed us to correlate performance enhancements with increased electrochemical surface area and preferential deposition of Au(110) and Au(111) sites, even in disparate Edep conditions. We validate our methodology by scaling the Edep process to larger electrodes and correlating intrinsic activity with product speciation via flow electrolysis measurements. Our platform highlights opportunities in automation for electrocatalyst discovery to address pressing needs toward industrial decarbonization, such as biomass valorization.
{"title":"Identifying Reactive Trends in Glycerol Electro-Oxidation Using an Automated Screening Approach: 28 Ways to Electrodeposit an Au Electrocatalyst","authors":"Raghuram Gaddam, Zirui Wang, Yichen Li, Lauren C. Harris, Michael A. Pence, Efren R. Guerrero, Paul J. A. Kenis, Andrew A. Gewirth, Joaquín Rodríguez-López","doi":"10.1021/acscatal.4c04190","DOIUrl":"https://doi.org/10.1021/acscatal.4c04190","url":null,"abstract":"Automated, rapid electrocatalyst discovery techniques that comprehensively address the exploration of chemical spaces, characterization of catalyst robustness, reproducibility, and translation of results to (flow) electrolysis operation are needed. Responding to the growing interest in biomass valorization, we studied the glycerol electro-oxidation reaction (GEOR) on gold in alkaline media as a model reaction to demonstrate the efficacy of such methodology introduced here. Our platform combines individually addressable electrode arrays with HardPotato, a Python application programming interface for potentiostat control, to automate electrochemical experiments and data analysis operations. We systematically investigated the effects of reduction potential (<i>E</i><sub>l</sub>) and pulse width (PW) on GEOR activity during the electrodeposition (Edep) of gold, evaluating 28 different conditions in triplicate measurements with great versatility. Our findings reveal a direct correlation between <i>E</i><sub>l</sub> and GEOR activity. Upon CV cycling, we recorded a 52% increase in peak current density and a −0.25 V shift in peak potential as <i>E</i><sub>l</sub> varied from −0.2 to −1.4 V. We also identified an optimal PW of ∼1.0 s, yielding maximum catalytic performance. The swift analysis enabled by our methodology allowed us to correlate performance enhancements with increased electrochemical surface area and preferential deposition of Au(110) and Au(111) sites, even in disparate Edep conditions. We validate our methodology by scaling the Edep process to larger electrodes and correlating intrinsic activity with product speciation via flow electrolysis measurements. Our platform highlights opportunities in automation for electrocatalyst discovery to address pressing needs toward industrial decarbonization, such as biomass valorization.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"27 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142880023","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 : 2024-12-23DOI: 10.1021/acscatal.4c06631
Jing He, Wan Seok Yoon, Jaesook Yun
The construction of congested acyclic stereocenters with high stereoselectivity is a significant challenge in synthetic chemistry. Herein, we report an efficient method for diastereo- and enantioselective C–C coupling of 1,3-disubstituted enynes with imines for the asymmetric construction of vicinal stereogenic centers, including an all-carbon quaternary center. This coupling was accomplished by chirality transfer from axial-to-central of fully substituted axially chiral allenylcopper intermediates formed in situ from branched enynes with concomitant diastereoselective formation of an additional stereocenter in imine addition enabled by a chiral C1-symmetric N-heterocyclic carbene (NHC) copper catalyst. DFT calculations provided an enhanced understanding of the silyl effect of allenylcopper nucleophiles on reactivity and the origin of stereoselectivity. Synthetic versatility of the resulting products bearing densely functionalized groups could amplify the significance of the current method.
{"title":"Cu-Catalyzed Diastereo- and Enantioselective Synthesis of Homopropargyl Amines Bearing All-Carbon Quaternary Stereocenters via Chirality Transfer of Hindered Allenylcopper Species","authors":"Jing He, Wan Seok Yoon, Jaesook Yun","doi":"10.1021/acscatal.4c06631","DOIUrl":"https://doi.org/10.1021/acscatal.4c06631","url":null,"abstract":"The construction of congested acyclic stereocenters with high stereoselectivity is a significant challenge in synthetic chemistry. Herein, we report an efficient method for diastereo- and enantioselective C–C coupling of 1,3-disubstituted enynes with imines for the asymmetric construction of vicinal stereogenic centers, including an all-carbon quaternary center. This coupling was accomplished by chirality transfer from axial-to-central of fully substituted axially chiral allenylcopper intermediates formed in situ from branched enynes with concomitant diastereoselective formation of an additional stereocenter in imine addition enabled by a chiral C<sub>1</sub>-symmetric <i>N</i>-heterocyclic carbene (NHC) copper catalyst. DFT calculations provided an enhanced understanding of the silyl effect of allenylcopper nucleophiles on reactivity and the origin of stereoselectivity. Synthetic versatility of the resulting products bearing densely functionalized groups could amplify the significance of the current method.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"83 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142873849","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 : 2024-12-23DOI: 10.1021/acscatal.4c06260
Ana C. Ebrecht, Jasmin C. Aschenbrenner, Yosephine Gumulya, Martha S. Smit, Diederik J. Opperman
Regioselective C–H functionalization of fatty acids and alcohols is a challenging reaction, especially in-chain/midchain hydroxylation. These hydroxy fatty acids or diols offer a synthetic route to valuable δ- and γ-lactones. Although terminal and subterminal hydroxylation of fatty acids and alcohols by cytochrome P450 monooxygenases have been extensively explored, the molecular determinants of in-chain hydroxylation are unknown. Here we performed ancestral sequence reconstruction (ASR) of the subfamily of CYP505Es, able to perform in-chain hydroxylation, together with their closest related subterminal hydroxylases. Three ancestors were resurrected, which represented the in-chain and subterminal hydroxylases, as well as their common ancestor, which displayed little regioselectivity. Mutations were introduced to investigate the divergence in regioselectivity observed in the natural evolution. Whereas subterminal hydroxylation appears to be through multiple additive mutations in the active site, in-chain hydroxylation was greatly affected by the BC-loop. ASR provides not only insight for directed evolution studies but also more promiscuous ancestors as templates for the starting point for laboratory evolution.
{"title":"Ancestral Sequence Reconstruction Reveals Determinants of Regioselectivity in C(sp3)-H Oxyfunctionalization Reactions by CYP505Es","authors":"Ana C. Ebrecht, Jasmin C. Aschenbrenner, Yosephine Gumulya, Martha S. Smit, Diederik J. Opperman","doi":"10.1021/acscatal.4c06260","DOIUrl":"https://doi.org/10.1021/acscatal.4c06260","url":null,"abstract":"Regioselective C–H functionalization of fatty acids and alcohols is a challenging reaction, especially in-chain/midchain hydroxylation. These hydroxy fatty acids or diols offer a synthetic route to valuable δ- and γ-lactones. Although terminal and subterminal hydroxylation of fatty acids and alcohols by cytochrome P450 monooxygenases have been extensively explored, the molecular determinants of in-chain hydroxylation are unknown. Here we performed ancestral sequence reconstruction (ASR) of the subfamily of CYP505Es, able to perform in-chain hydroxylation, together with their closest related subterminal hydroxylases. Three ancestors were resurrected, which represented the in-chain and subterminal hydroxylases, as well as their common ancestor, which displayed little regioselectivity. Mutations were introduced to investigate the divergence in regioselectivity observed in the natural evolution. Whereas subterminal hydroxylation appears to be through multiple additive mutations in the active site, in-chain hydroxylation was greatly affected by the BC-loop. ASR provides not only insight for directed evolution studies but also more promiscuous ancestors as templates for the starting point for laboratory evolution.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"60 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142873847","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}
Rare-earth-promoted zeolites have broad applications in the petrochemical industry because modifying zeolites with rare-earth elements can remarkably improve hydrothermal stability and tune the physicochemical properties of the acid sites, resulting in substantial promotion in catalytic selectivity and long-term stability. However, for a specific reaction, it remains a challenge to elaborate the coordination environment of rare-earth elements within the zeolite structure and establish the structure–reactivity of rare-earth-promoted zeolite catalysts. In this work, we have employed multiple spectroscopy and electron microscopy techniques to elucidate the spatial location and coordination environment of atomically dispersed La species in MCM-22 concertedly. In particular, we have attempted to clarify the variation of the chemical nature of the acid sites in MCM-22 zeolite in response to the introduction of La promotor. By appropriately controlling the spatial distribution and chemical nature of the acid sites, we have obtained a La-modified MCM-22 catalyst with high activity, selectivity, and long-term stability (>800 h) for alkylation of 2-methylnaphthalene with methanol for the production of 2,6-dimethyl-naphthalene under industrially relevant conditions.
{"title":"Tuning the Spatial Distribution and Chemical Nature of Acid Sites in MCM-22 Zeolite by Atomically Dispersed Lanthanum Species for Alkylation of 2-Methylnaphthalene","authors":"Yaxing Li, Xiaoyu Li, Haotian Zhang, Jiayi He, Kaining Su, Tianxiang Chen, Ruolin Zhang, Hua Xu, Yuchao Wu, Weisheng Yang, Lichen Liu","doi":"10.1021/acscatal.4c07304","DOIUrl":"https://doi.org/10.1021/acscatal.4c07304","url":null,"abstract":"Rare-earth-promoted zeolites have broad applications in the petrochemical industry because modifying zeolites with rare-earth elements can remarkably improve hydrothermal stability and tune the physicochemical properties of the acid sites, resulting in substantial promotion in catalytic selectivity and long-term stability. However, for a specific reaction, it remains a challenge to elaborate the coordination environment of rare-earth elements within the zeolite structure and establish the structure–reactivity of rare-earth-promoted zeolite catalysts. In this work, we have employed multiple spectroscopy and electron microscopy techniques to elucidate the spatial location and coordination environment of atomically dispersed La species in MCM-22 concertedly. In particular, we have attempted to clarify the variation of the chemical nature of the acid sites in MCM-22 zeolite in response to the introduction of La promotor. By appropriately controlling the spatial distribution and chemical nature of the acid sites, we have obtained a La-modified MCM-22 catalyst with high activity, selectivity, and long-term stability (>800 h) for alkylation of 2-methylnaphthalene with methanol for the production of 2,6-dimethyl-naphthalene under industrially relevant conditions.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"13 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142873852","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}
Herein, we demonstrate a one-pot sol–gel-assisted procedure to prepare a defect-rich Li2WO4/Mg6MnO8 catalyst having surface oxygen vacancies, which facilitates the adsorption of O2 molecules to generate active oxygen species (O2–, O22–) by incorporating Li and W into the Mg6MnO8 lattice. These active oxygen species serve as primary active sites, selectively dissociating CH4 into CH3• and promoting CH3• coupling into C2H6, while hindering excessive oxidation of CH3• into COx. Various analytical methods such as XPS, O2-TPD, EPR, CH4-TPSR, in situ DRIFTS, and in situ Raman spectroscopy studies demonstrated that surface reactive oxygen species are more active and selective than lattice oxygen toward the formation of C2 products. The controlled addition of Li and W plays a crucial role in stabilizing surface Li species through the formation of Li–O–W bonds by forming the Li2WO4 phase, ensuring stable catalyst performance up to 100 h. DOS analysis shows a positive shift in the p-band center, which effectively promotes the formation of oxygen vacancies. Analytical studies confirmed that surface active oxygen species are more active and selective than lattice oxygen in forming C2 hydrocarbons. The Li2WO4/Mg6MnO8 catalyst exhibited superior performance, achieving ∼82% C2 selectivity and ∼25% C2 yield at 700 °C. We found that the stable formation of active oxygen species (O2–) and a high Mn4+/Mn3+ ratio over the surface are the key factors for achieving high C2 selectivity and yield during OCM. DFT results show that the concentration of oxygen defect sites is higher on the surface of the Li2WO4/Mg6MnO8 catalyst, which synergistically binds Li2WO4 and Mg6MnO8, in comparison with pure Mg6MnO8 surfaces. Furthermore, DFT calculations also indicate that oxygen vacancies are energetically more favorable on the surface of the Li2WO4/Mg6MnO8 catalyst rather than in its subsurface. In situ XRD and in situ Raman analysis demonstrated that Li2WO4 undergoes a reversible phase change, transitioning into a molten state at higher temperatures, potentially forming Li2O2 species that may serve as active centers during the reaction.
{"title":"Optimizing Oxygen Vacancies through p-Band Center Modulation of Oxygen in the Li2WO4/Mg6MnO8 Catalyst for Enhanced Oxidative Coupling of Methane: An Experimental and Theoretical Study","authors":"Rohan Singh Pal, Rubina Khatun, Jyotishman Kaishyop, Sachin Kumar Sharma, Swati Rana, Shivani Singh, Anil Chandra Kothari, Tuhin Suvra Khan, Shailendra Tripathi, Suman Sarkar, Rajaram Bal","doi":"10.1021/acscatal.4c06709","DOIUrl":"https://doi.org/10.1021/acscatal.4c06709","url":null,"abstract":"Herein, we demonstrate a one-pot sol–gel-assisted procedure to prepare a defect-rich Li<sub>2</sub>WO<sub>4</sub>/Mg<sub>6</sub>MnO<sub>8</sub> catalyst having surface oxygen vacancies, which facilitates the adsorption of O<sub>2</sub> molecules to generate active oxygen species (O<sub>2</sub><sup>–</sup>, O<sub>2</sub><sup>2–</sup>) by incorporating Li and W into the Mg<sub>6</sub>MnO<sub>8</sub> lattice. These active oxygen species serve as primary active sites, selectively dissociating CH<sub>4</sub> into CH<sub>3</sub><sup>•</sup> and promoting CH<sub>3</sub><sup>•</sup> coupling into C<sub>2</sub>H<sub>6</sub>, while hindering excessive oxidation of CH<sub>3</sub><sup>•</sup> into CO<sub><i>x</i></sub>. Various analytical methods such as XPS, O<sub>2</sub>-TPD, EPR, CH<sub>4</sub>-TPSR, in situ DRIFTS, and in situ Raman spectroscopy studies demonstrated that surface reactive oxygen species are more active and selective than lattice oxygen toward the formation of C<sub>2</sub> products. The controlled addition of Li and W plays a crucial role in stabilizing surface Li species through the formation of Li–O–W bonds by forming the Li<sub>2</sub>WO<sub>4</sub> phase, ensuring stable catalyst performance up to 100 h. DOS analysis shows a positive shift in the p-band center, which effectively promotes the formation of oxygen vacancies. Analytical studies confirmed that surface active oxygen species are more active and selective than lattice oxygen in forming C<sub>2</sub> hydrocarbons. The Li<sub>2</sub>WO<sub>4</sub>/Mg<sub>6</sub>MnO<sub>8</sub> catalyst exhibited superior performance, achieving ∼82% C<sub>2</sub> selectivity and ∼25% C<sub>2</sub> yield at 700 °C. We found that the stable formation of active oxygen species (O<sub>2</sub><sup>–</sup>) and a high Mn<sup>4+</sup>/Mn<sup>3+</sup> ratio over the surface are the key factors for achieving high C<sub>2</sub> selectivity and yield during OCM. DFT results show that the concentration of oxygen defect sites is higher on the surface of the Li<sub>2</sub>WO<sub>4</sub>/Mg<sub>6</sub>MnO<sub>8</sub> catalyst, which synergistically binds Li<sub>2</sub>WO<sub>4</sub> and Mg<sub>6</sub>MnO<sub>8</sub>, in comparison with pure Mg<sub>6</sub>MnO<sub>8</sub> surfaces. Furthermore, DFT calculations also indicate that oxygen vacancies are energetically more favorable on the surface of the Li<sub>2</sub>WO<sub>4</sub>/Mg<sub>6</sub>MnO<sub>8</sub> catalyst rather than in its subsurface. In situ XRD and in situ Raman analysis demonstrated that Li<sub>2</sub>WO<sub>4</sub> undergoes a reversible phase change, transitioning into a molten state at higher temperatures, potentially forming Li<sub>2</sub>O<sub>2</sub> species that may serve as active centers during the reaction.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"48 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142873851","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 oxidation of ethylene glycol (EG) derived from polyethylene terephthalate (PET) plastic into value-added chemicals, coupled with hydrogen evolution, offers a promising approach to addressing plastic pollution. However, the mechanisms by which the adsorption of key reaction intermediates affects the EG oxidation reaction (EGOR) are not well understood. To investigate this, we synthesized two model catalysts: amorphous-phase CoNiOOH/NF and CoNiOOH–Ni3S2/NF with an amorphous/crystalline interface. Detailed characterizations and theoretical calculations demonstrate that the amorphous/crystalline interface in CoNiOOH–Ni3S2/NF shifts the d-band center upward, enhancing the adsorption of EG and *OH compared to amorphous CoNiOOH/NF. Enhanced *OH adsorption is crucial for promoting C–C bond cleavage and subsequent dehydrogenation. In situ electrochemical infrared absorption spectroscopy (IRAS) and theoretical calculations reveal that formate (FA) is primarily formed through cleavage of the C–C bond in glycolic acid, followed by oxidation. Notably, CoNiOOH–Ni3S2/NF achieves industrial-level current densities of 500 mA cm–2 at an ultralow potential of 1.45 V vs RHE, with a Faradaic efficiency (FE) of 96.6% and FA productivity of 3.14 mmol cm–2 h–1 at 1.70 V vs RHE. This study offers valuable insights for designing efficient heterojunction catalysts for the electrochemical upcycling of PET plastics.
{"title":"Promoted *OH Adsorption Facilitates C–C Bond Cleavage for Efficient Electrochemical Upcycling of Polyethylene Terephthalate","authors":"Jinyong Sun, Binkai Shi, Shuixing Dai, Lei Chu, Huanlei Wang, Minghua Huang","doi":"10.1021/acscatal.4c05352","DOIUrl":"https://doi.org/10.1021/acscatal.4c05352","url":null,"abstract":"The electrochemical oxidation of ethylene glycol (EG) derived from polyethylene terephthalate (PET) plastic into value-added chemicals, coupled with hydrogen evolution, offers a promising approach to addressing plastic pollution. However, the mechanisms by which the adsorption of key reaction intermediates affects the EG oxidation reaction (EGOR) are not well understood. To investigate this, we synthesized two model catalysts: amorphous-phase CoNiOOH/NF and CoNiOOH–Ni<sub>3</sub>S<sub>2</sub>/NF with an amorphous/crystalline interface. Detailed characterizations and theoretical calculations demonstrate that the amorphous/crystalline interface in CoNiOOH–Ni<sub>3</sub>S<sub>2</sub>/NF shifts the d-band center upward, enhancing the adsorption of EG and *OH compared to amorphous CoNiOOH/NF. Enhanced *OH adsorption is crucial for promoting C–C bond cleavage and subsequent dehydrogenation. In situ electrochemical infrared absorption spectroscopy (IRAS) and theoretical calculations reveal that formate (FA) is primarily formed through cleavage of the C–C bond in glycolic acid, followed by oxidation. Notably, CoNiOOH–Ni<sub>3</sub>S<sub>2</sub>/NF achieves industrial-level current densities of 500 mA cm<sup>–2</sup> at an ultralow potential of 1.45 V vs RHE, with a Faradaic efficiency (FE) of 96.6% and FA productivity of 3.14 mmol cm<sup>–2</sup> h<sup>–1</sup> at 1.70 V vs RHE. This study offers valuable insights for designing efficient heterojunction catalysts for the electrochemical upcycling of PET plastics.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"75 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142858191","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}
A catalytic asymmetric intermolecular benzylic C–H amination was achieved under paddle-wheel diruthenium catalysis. A chiral diruthenium catalyst incorporating (S)-TPPTTL (tetraphenylphthaloyl-(S)-tert-leucine) ligand exhibited notable enantioselectivity, and aminated products were obtained with up to 99% ee. Unique chemoselectivity of the chiral diruthenium catalyst was also found for allylbenzene and alkyl-naphthalene substrates, demonstrating the complementary synthetic utility of chiral paddle-wheel Ru(II)–Ru(III) catalysts to Rh(II) counterparts.
{"title":"Enantioselective Intermolecular Benzylic C–H Amination under Chiral Paddle-Wheel Diruthenium Catalysis","authors":"Kotoko Makino, Kohei Mori, Shoichi Kiryu, Taku Miyazawa, Yuhei Kumagai, Kosuke Higashida, Masahiro Kojima, Tatsuhiko Yoshino, Shigeki Matsunaga","doi":"10.1021/acscatal.4c06504","DOIUrl":"https://doi.org/10.1021/acscatal.4c06504","url":null,"abstract":"A catalytic asymmetric intermolecular benzylic C–H amination was achieved under paddle-wheel diruthenium catalysis. A chiral diruthenium catalyst incorporating (<i>S</i>)-TPPTTL (tetraphenylphthaloyl-(<i>S</i>)-<i>tert</i>-leucine) ligand exhibited notable enantioselectivity, and aminated products were obtained with up to 99% ee. Unique chemoselectivity of the chiral diruthenium catalyst was also found for allylbenzene and alkyl-naphthalene substrates, demonstrating the complementary synthetic utility of chiral paddle-wheel Ru(II)–Ru(III) catalysts to Rh(II) counterparts.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"41 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142858118","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 : 2024-12-20DOI: 10.1021/acscatal.4c06414
Patricia Poths, King Chun Lai, Francesco Cannizzaro, Christoph Scheurer, Sebastian Matera, Karsten Reuter
We combine automatic process exploration with an iteratively trained machine-learning interatomic potential to systematically identify elementary processes occurring during the initial oxidation of a Pd step edge. Corresponding process lists are a prerequisite to overcome prevalent predictive-quality microkinetic modeling approaches which consider only a minimum number of hand-selected and thus typically intuitive processes. The exploration readily generates close to 3000 inequivalent elementary processes and thus unveils a complexity far beyond current microkinetic modeling capabilities. Among these processes are numerous low-barrier processes involving the collective motion of several atoms that enable a facile O-mediated restructuring of the Pd step edge through the motion of larger PdxOy units. The concomitant interconversion happens on time scales comparable to those of molecular processes of heterogeneous oxidation catalysis. This suggests a dynamic aspect of the operando evolution of the working interface reminiscent of the fluxionality discussed in nanocluster catalysis.
我们将自动过程探索与迭代训练的机器学习原子间势能相结合，系统地识别了钯阶梯边缘初始氧化过程中发生的基本过程。相应的过程列表是克服流行的具有预测质量的微动力学建模方法的先决条件，这些方法只考虑了最少数量的手工选择的过程，因此通常比较直观。通过探索，可以轻松生成近 3000 个不等价的基本过程，从而揭示了远远超出当前微观动力学建模能力的复杂性。在这些过程中，有许多涉及多个原子集体运动的低阻力过程，通过较大的 PdxOy 单元的运动，这些过程使 O 介导的钯阶跃边的重组变得容易。同时发生的相互转化的时间尺度与异相氧化催化的分子过程相当。这表明工作界面的动态演化与纳米簇催化中讨论的通性相似。
{"title":"ML-Accelerated Automatic Process Exploration Reveals Facile O-Induced Pd Step-Edge Restructuring on Catalytic Time Scales","authors":"Patricia Poths, King Chun Lai, Francesco Cannizzaro, Christoph Scheurer, Sebastian Matera, Karsten Reuter","doi":"10.1021/acscatal.4c06414","DOIUrl":"https://doi.org/10.1021/acscatal.4c06414","url":null,"abstract":"We combine automatic process exploration with an iteratively trained machine-learning interatomic potential to systematically identify elementary processes occurring during the initial oxidation of a Pd step edge. Corresponding process lists are a prerequisite to overcome prevalent predictive-quality microkinetic modeling approaches which consider only a minimum number of hand-selected and thus typically intuitive processes. The exploration readily generates close to 3000 inequivalent elementary processes and thus unveils a complexity far beyond current microkinetic modeling capabilities. Among these processes are numerous low-barrier processes involving the collective motion of several atoms that enable a facile O-mediated restructuring of the Pd step edge through the motion of larger Pd<sub><i>x</i></sub>O<sub><i>y</i></sub> units. The concomitant interconversion happens on time scales comparable to those of molecular processes of heterogeneous oxidation catalysis. This suggests a dynamic aspect of the <i>operando</i> evolution of the working interface reminiscent of the fluxionality discussed in nanocluster catalysis.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"11 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142858189","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 : 2024-12-20DOI: 10.1021/acscatal.4c05826
Pran Gobinda Nandi, Pabitra Maity, Akshai Kumar
The net-decarboxylative coupling of low-molecular weight alcohols to high-molecular weight alkanes has been investigated using a series of NNN pincer-Ru catalysts based on bis(imino)pyridine and 2,6-bis(benzimidazole-2-yl)pyridine ligands. Notably, a majority of the considered pincer-Ru complexes, including the Ru precursors, were either not very active or were unselective giving alkene/alkane mixtures. However, in the presence of 0.5 equiv of NaOH in toluene at 140 °C, the complex (MeBim2NNN)RuCl2(PPh3)2 based on the 2,6-bis(benzimidazole-2-yl)pyridine ligand demonstrated very high activity giving up to 91% yield with 100% selectivity toward the alkane (1,3-diphenyl propane) starting from 2-phenyl ethanol after 24 h of reaction. On the other hand, the complex (iPr2NNN)RuCl2(PPh3) based on the bis(imino)pyridine ligand was found to be the least active and gave 14% 1,3-diphenyl propane at 25% selectivity. Experimental mechanistic studies point to the evolution of hydrogen (detected by GC) and formic acid (detected by 1H NMR) during the reaction along with the involvement of organic intermediates such as α,β-unsaturated aldehydes. The [(MeBim2NNN)RuCl(PPh3)2]Cl catalyzed transformation of 2-phenyl ethanol to 1,3-diphenyl propane demonstrated a first-order dependence of the initial rate on the concentration of both the catalyst and the base. While catalyst poisoning experiments with Hg revealed the homogeneous and well-defined molecular nature of the catalyst, a few of these molecular species, including the resting state (MeBim2NNN)RuHCl (experimentally trapped as its PPh3 adduct), have been identified by HRMS analysis and NMR studies. DFT studies complement the experimental findings and indicate that in the more favorable hydrogenolysis path, the dehydrogenolysis step is rate-determining (ΔG140‡ = 22.81 kcal/mol), and it leads to the formation of 2-phenyl acetaldehyde along with the resting state (MeBim2NNN)RuHCl. On the other hand, the corresponding cycle with the least active catalyst (iPr2NNN)RuCl2(PPh3) that involved the insertion of 1,3-diphenyl propene into the Ru–H bond as the RDS had a relatively more unfavorable barrier of 27.81 kcal/mol. This work that provides direct access to jet-fuel-grade 1,3-diphenyl propane starting from 2-phenyl ethanol in a single-step, one-pot strategy offers great promise to open up exciting opportunities in this very important field of study.
{"title":"Pincer-Ruthenium-Catalyzed Direct Formation of Fuel-Grade Alkanes via a Net-Decarboxylative Coupling of Alcohols","authors":"Pran Gobinda Nandi, Pabitra Maity, Akshai Kumar","doi":"10.1021/acscatal.4c05826","DOIUrl":"https://doi.org/10.1021/acscatal.4c05826","url":null,"abstract":"The net-decarboxylative coupling of low-molecular weight alcohols to high-molecular weight alkanes has been investigated using a series of NNN pincer-Ru catalysts based on bis(imino)pyridine and 2,6-bis(benzimidazole-2-yl)pyridine ligands. Notably, a majority of the considered pincer-Ru complexes, including the Ru precursors, were either not very active or were unselective giving alkene/alkane mixtures. However, in the presence of 0.5 equiv of NaOH in toluene at 140 °C, the complex (<sup>MeBim2</sup>NNN)RuCl<sub>2</sub>(PPh<sub>3</sub>)<sub>2</sub> based on the 2,6-bis(benzimidazole-2-yl)pyridine ligand demonstrated very high activity giving up to 91% yield with 100% selectivity toward the alkane (1,3-diphenyl propane) starting from 2-phenyl ethanol after 24 h of reaction. On the other hand, the complex (<sup><i>i</i>Pr2</sup>NNN)RuCl<sub>2</sub>(PPh<sub>3</sub>) based on the bis(imino)pyridine ligand was found to be the least active and gave 14% 1,3-diphenyl propane at 25% selectivity. Experimental mechanistic studies point to the evolution of hydrogen (detected by GC) and formic acid (detected by <sup>1</sup>H NMR) during the reaction along with the involvement of organic intermediates such as α,β-unsaturated aldehydes. The [(<sup>MeBim2</sup>NNN)RuCl(PPh<sub>3</sub>)<sub>2</sub>]Cl catalyzed transformation of 2-phenyl ethanol to 1,3-diphenyl propane demonstrated a first-order dependence of the initial rate on the concentration of both the catalyst and the base. While catalyst poisoning experiments with Hg revealed the homogeneous and well-defined molecular nature of the catalyst, a few of these molecular species, including the resting state (<sup>MeBim2</sup>NNN)RuHCl (experimentally trapped as its PPh<sub>3</sub> adduct), have been identified by HRMS analysis and NMR studies. DFT studies complement the experimental findings and indicate that in the more favorable hydrogenolysis path, the dehydrogenolysis step is rate-determining (Δ<i>G</i><sub>140</sub><sup>‡</sup> = 22.81 kcal/mol), and it leads to the formation of 2-phenyl acetaldehyde along with the resting state (<sup>MeBim2</sup>NNN)RuHCl. On the other hand, the corresponding cycle with the least active catalyst (<sup><i>i</i>Pr2</sup>NNN)RuCl<sub>2</sub>(PPh<sub>3</sub>) that involved the insertion of 1,3-diphenyl propene into the Ru–H bond as the RDS had a relatively more unfavorable barrier of 27.81 kcal/mol. This work that provides direct access to jet-fuel-grade 1,3-diphenyl propane starting from 2-phenyl ethanol in a single-step, one-pot strategy offers great promise to open up exciting opportunities in this very important field of study.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"24 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142866989","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：