Pub Date : 2024-09-18DOI: 10.1021/acscatal.4c04187
Sebastiano Gadolini, Rachel N. Kerber, Riho T. Seljamäe-Green, Wenming Tong, Pau Farràs, Elena C. Corbos
This study explores an innovative photocatalytic approach using pristine graphitic carbon nitride (C3N4) to anchor iron salen-type complexes (FeSalenCl2) without the need for additional linkers or heterojunctions. The resulting hybrid catalyst, [C3N4-FeCl(Salen)]Chem, exhibits a promising catalytic performance in the selective epoxidation of cyclic and linear olefins using gaseous oxygen as the oxidant. The catalyst’s selectivity closely resembles that of the free iron complex, and its effectiveness varies depending on the olefin substrate. Additionally, solvent selection plays a critical role in achieving optimal performance, with acetonitrile proving to be the best choice. The study demonstrates the potential of C3N4 as an environmentally friendly, recyclable, and efficient support for molecular catalysts. The results highlight the versatility and significance of C3N4-based materials in advancing light-driven catalysis.
{"title":"Covalently Anchored Molecular Catalyst onto a Graphitic Carbon Nitride Surface for Photocatalytic Epoxidation of Olefins","authors":"Sebastiano Gadolini, Rachel N. Kerber, Riho T. Seljamäe-Green, Wenming Tong, Pau Farràs, Elena C. Corbos","doi":"10.1021/acscatal.4c04187","DOIUrl":"https://doi.org/10.1021/acscatal.4c04187","url":null,"abstract":"This study explores an innovative photocatalytic approach using pristine graphitic carbon nitride (C<sub>3</sub>N<sub>4</sub>) to anchor iron salen-type complexes (FeSalenCl<sub>2</sub>) without the need for additional linkers or heterojunctions. The resulting hybrid catalyst, [C<sub>3</sub>N<sub>4</sub>-FeCl(Salen)]<sub>Chem</sub>, exhibits a promising catalytic performance in the selective epoxidation of cyclic and linear olefins using gaseous oxygen as the oxidant. The catalyst’s selectivity closely resembles that of the free iron complex, and its effectiveness varies depending on the olefin substrate. Additionally, solvent selection plays a critical role in achieving optimal performance, with acetonitrile proving to be the best choice. The study demonstrates the potential of C<sub>3</sub>N<sub>4</sub> as an environmentally friendly, recyclable, and efficient support for molecular catalysts. The results highlight the versatility and significance of C<sub>3</sub>N<sub>4</sub>-based materials in advancing light-driven catalysis.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":null,"pages":null},"PeriodicalIF":12.9,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142237304","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 : 2024-09-18DOI: 10.1021/acscatal.4c04922
Heng-Quan Chen, Wanghui Zhao, Linqin Wang, Zhong Chen, Wentao Ye, Jianyang Zang, Tao Wang, Licheng Sun, Wenxing Yang
In the original Supporting Information, the name of instruments used for X-ray absorption spectroscopy measurements was inaccurately described. The XAFS spectra of Cu k-edge and XANES spectra of Ce L3-edge were obtained from two different Table XAFS instruments. An amended version of the Supporting Information is now provided to correct the name of the instruments with further experimental details. The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acscatal.4c04922. Experimental procedures, XAS data and the fitting results, large-current device tests, ECSA, the whole in situ ATR-SEIRA spectra of catalysts, density functional theory calculations (PDF) Correction to “Origin of Metal-Support Interactions for Selective Electrochemical CO2 Reduction into C1 and C2+ Products” 2 views 0 shares 0 downloads Most electronic Supporting Information files are available without a subscription to ACS Web Editions. Such files may be downloaded by article for research use (if there is a public use license linked to the relevant article, that license may permit other uses). Permission may be obtained from ACS for other uses through requests via the RightsLink permission system: http://pubs.acs.org/page/copyright/permissions.html. This article has not yet been cited by other publications.
在原始佐证资料中，用于 X 射线吸收光谱测量的仪器名称描述不准确。Cu k-edge 的 XAFS 光谱和 Ce L3-edge 的 XANES 光谱是通过两台不同的 Table XAFS 仪器获得的。现提供修订版的佐证资料，以更正仪器名称和进一步的实验细节。辅助信息可在 https://pubs.acs.org/doi/10.1021/acscatal.4c04922 免费获取。实验过程、XAS 数据和拟合结果、大电流装置测试、ECSA、催化剂的整个原位 ATR-SEIRA 光谱、密度泛函理论计算 (PDF) 更正为 "Originof Metal-Support Interactionsfor Selective Electrochemical CO2 Reduction into C1 and C2+ Products" 2 次浏览 0 次分享 0 次下载 大多数电子版辅助信息文件无需订阅 ACS Web Editions 即可获得。这些文件可按文章下载用于研究（如果相关文章有公共使用许可链接，该许可可能允许其他用途）。如需其他用途，可通过 RightsLink 许可系统 http://pubs.acs.org/page/copyright/permissions.html 向 ACS 申请许可。本文尚未被其他出版物引用。
{"title":"Correction to “Origin of Metal-Support Interactions for Selective Electrochemical CO2 Reduction into C1 and C2+ Products”","authors":"Heng-Quan Chen, Wanghui Zhao, Linqin Wang, Zhong Chen, Wentao Ye, Jianyang Zang, Tao Wang, Licheng Sun, Wenxing Yang","doi":"10.1021/acscatal.4c04922","DOIUrl":"https://doi.org/10.1021/acscatal.4c04922","url":null,"abstract":"In the original Supporting Information, the name of instruments used for X-ray absorption spectroscopy measurements was inaccurately described. The XAFS spectra of Cu k-edge and XANES spectra of Ce L3-edge were obtained from two different Table XAFS instruments. An amended version of the Supporting Information is now provided to correct the name of the instruments with further experimental details. The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acscatal.4c04922. Experimental procedures, XAS data and the fitting results, large-current device tests, ECSA, the whole in situ ATR-SEIRA spectra of catalysts, density functional theory calculations (PDF) Correction to “Origin\u0000of Metal-Support Interactions\u0000for Selective Electrochemical CO<sub>2</sub> Reduction into C<sub>1</sub> and C<sub>2+</sub> Products” <span> 2 </span><span> views </span> <span> 0 </span><span> shares </span> <span> 0 </span><span> downloads </span> Most electronic Supporting Information files are available without a subscription to ACS Web Editions. Such files may be downloaded by article for research use (if there is a public use license linked to the relevant article, that license may permit other uses). Permission may be obtained from ACS for other uses through requests via the RightsLink permission system: http://pubs.acs.org/page/copyright/permissions.html. This article has not yet been cited by other publications.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":null,"pages":null},"PeriodicalIF":12.9,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142273622","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 : 2024-09-18DOI: 10.1021/acscatal.4c01920
Simone Perego, Luigi Bonati, Shivam Tripathi, Michele Parrinello
Being rich in hydrogen and easy to transport, ammonia is a promising hydrogen carrier. However, a microscopic characterization of the ammonia cracking reaction is still lacking, hindered by extreme operando conditions. Leveraging state-of-the-art molecular dynamics, machine learning potentials, and enhanced sampling methods, we offer an atomistic view of the adsorption, diffusion, and dehydrogenation processes of a single NHx (x = 1, 3) molecule on two representative surfaces at the operando temperature of 700 K. We elucidate the effects of the dynamics on all the steps of decomposition. On the stable (110) surface, we found that the reaction intermediate diffusions are favored over dehydrogenation, with non-negligible effects on the reactivity for one intermediate. The role is even more dramatic on the (111) surface, where the mobility of Fe surface atoms introduces unexplored adsorption sites and significantly alters the dehydrogenation barriers. In both cases, a detailed analysis of reactive events shows that there is never a single transition state, but it is always an ensemble. Notwithstanding, a unified mechanism can be identified by following the charge transfer along the different reaction pathways.
{"title":"How Dynamics Changes Ammonia Cracking on Iron Surfaces","authors":"Simone Perego, Luigi Bonati, Shivam Tripathi, Michele Parrinello","doi":"10.1021/acscatal.4c01920","DOIUrl":"https://doi.org/10.1021/acscatal.4c01920","url":null,"abstract":"Being rich in hydrogen and easy to transport, ammonia is a promising hydrogen carrier. However, a microscopic characterization of the ammonia cracking reaction is still lacking, hindered by extreme <i>operando</i> conditions. Leveraging state-of-the-art molecular dynamics, machine learning potentials, and enhanced sampling methods, we offer an atomistic view of the adsorption, diffusion, and dehydrogenation processes of a single NH<sub><i>x</i></sub> (<i>x</i> = 1, 3) molecule on two representative surfaces at the <i>operando</i> temperature of 700 K. We elucidate the effects of the dynamics on all the steps of decomposition. On the stable (110) surface, we found that the reaction intermediate diffusions are favored over dehydrogenation, with non-negligible effects on the reactivity for one intermediate. The role is even more dramatic on the (111) surface, where the mobility of Fe surface atoms introduces unexplored adsorption sites and significantly alters the dehydrogenation barriers. In both cases, a detailed analysis of reactive events shows that there is never a single transition state, but it is always an ensemble. Notwithstanding, a unified mechanism can be identified by following the charge transfer along the different reaction pathways.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":null,"pages":null},"PeriodicalIF":12.9,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142273625","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 : 2024-09-18DOI: 10.1021/acscatal.4c03380
Jiafu Li, Yanran Feng, Xingyun Li, Tianjun Zhang, Xia Liu, Ning Wang, Qiming Sun
Ultrafine metal alloy nanoparticles are emerging as highly effective catalysts for the generation of hydrogen from ammonia borane (AB) hydrolysis. The fabrication of multimetallic alloys with high activity, stability, and metal utilization remains the biggest challenge. Herein, sub-2 nm ternary Rh–Ru–Ni alloys were encapsulated within the interlayers of layer-stripped montmorillonite (MMT) via a simple impregnation method. Experiment and theory results revealed that the synergistic effect of the trimetallic alloy significantly lowers the energy barrier for the AB hydrolysis reaction, by boosting the adsorption and O–H dissociation of H2O molecules. The optimized Rh0.8Ru0.2Ni0.25@MMT-S catalyst achieves high turnover frequency values of 2961 and 784 min–1 at 298 and 273 K, respectively, as well as high recycling stability and thermal resistance. Moreover, the encapsulation method has versatility and can be also applied to synthesize ultrafine Pt- and Ir-based nanoparticles. This study not only highlights the role of the synergistic effect in trimetallic alloys for improving hydrogen evolution but also offers a route to design highly efficient and stable metal nanocatalysts for other applications.
超细金属合金纳米粒子正在成为氨硼烷（AB）水解制氢的高效催化剂。如何制造具有高活性、稳定性和金属利用率的多金属合金仍然是最大的挑战。本文通过一种简单的浸渍方法，在层状剥离蒙脱石（MMT）的夹层中封装了亚 2 nm 的三元 Rh-Ru-Ni 合金。实验和理论结果表明，三金属合金的协同效应通过促进 H2O 分子的吸附和 O-H 解离，显著降低了 AB 水解反应的能垒。优化后的 Rh0.8Ru0.2Ni0.25@MMT-S 催化剂在 298 K 和 273 K 条件下分别实现了 2961 和 784 min-1 的高周转频率值，以及较高的回收稳定性和耐热性。此外，该封装方法具有多功能性，还可用于合成超细铂基和铱基纳米颗粒。这项研究不仅强调了三金属合金的协同效应在改善氢气进化方面的作用，而且为设计用于其他应用的高效稳定的金属纳米催化剂提供了一条途径。
{"title":"Sub-2 nm Ternary Metallic Alloy Encapsulated within Montmorillonite Interlayers for Efficient Hydrogen Generation from Ammonia Borane Hydrolysis","authors":"Jiafu Li, Yanran Feng, Xingyun Li, Tianjun Zhang, Xia Liu, Ning Wang, Qiming Sun","doi":"10.1021/acscatal.4c03380","DOIUrl":"https://doi.org/10.1021/acscatal.4c03380","url":null,"abstract":"Ultrafine metal alloy nanoparticles are emerging as highly effective catalysts for the generation of hydrogen from ammonia borane (AB) hydrolysis. The fabrication of multimetallic alloys with high activity, stability, and metal utilization remains the biggest challenge. Herein, sub-2 nm ternary Rh–Ru–Ni alloys were encapsulated within the interlayers of layer-stripped montmorillonite (MMT) via a simple impregnation method. Experiment and theory results revealed that the synergistic effect of the trimetallic alloy significantly lowers the energy barrier for the AB hydrolysis reaction, by boosting the adsorption and O–H dissociation of H<sub>2</sub>O molecules. The optimized Rh<sub>0.8</sub>Ru<sub>0.2</sub>Ni<sub>0.25</sub>@MMT-S catalyst achieves high turnover frequency values of 2961 and 784 min<sup>–1</sup> at 298 and 273 K, respectively, as well as high recycling stability and thermal resistance. Moreover, the encapsulation method has versatility and can be also applied to synthesize ultrafine Pt- and Ir-based nanoparticles. This study not only highlights the role of the synergistic effect in trimetallic alloys for improving hydrogen evolution but also offers a route to design highly efficient and stable metal nanocatalysts for other applications.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":null,"pages":null},"PeriodicalIF":12.9,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142237097","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 : 2024-09-18DOI: 10.1021/acscatal.4c03785
Jun Long, Dong Luan, Xiaoyan Fu, Huan Li, Jianping Xiao
Recently, electrochemical coreduction of CO2 and NOx has been proposed as a sustainable route for urea synthesis. Although Zn is the best monometallic catalyst, the urea selectivity on Zn is very low. Toward the rational design of catalysts, the reaction mechanism of urea synthesis was unveiled based on an “electric field controlling constant potential” method, which can directly address the effects of explicit solvent, electric field, and electrode potential on reaction intermediates and transition states. We found that the couplings between CO* and NOH* and CONH* and N* are most favorable for the formation of two C–N bonds of urea, respectively. According to this mechanism, we not only reproduced the experimental Faradaic efficiencies of different products on Zn but also rationalized the activity trend of urea synthesis over a set of catalysts. More interestingly, we have revealed that adsorbed N* species on Fe and Mo have an essential promotion on urea production. Guided by the mechanistic insights, we finally proposed a compressive strain engineering to tune the d-band center of Zn, which can decrease the two C–N coupling barriers to 0.06 and 0 eV, respectively, and deliver a remarkable urea Faradaic efficiency (FE) of 88.5% using CO and NO as reactants.
{"title":"Theoretical Design of the Electrocatalytic Urea Synthesis from Carbon Dioxide and Nitric Oxides","authors":"Jun Long, Dong Luan, Xiaoyan Fu, Huan Li, Jianping Xiao","doi":"10.1021/acscatal.4c03785","DOIUrl":"https://doi.org/10.1021/acscatal.4c03785","url":null,"abstract":"Recently, electrochemical coreduction of CO<sub>2</sub> and NO<sub><i>x</i></sub> has been proposed as a sustainable route for urea synthesis. Although Zn is the best monometallic catalyst, the urea selectivity on Zn is very low. Toward the rational design of catalysts, the reaction mechanism of urea synthesis was unveiled based on an “electric field controlling constant potential” method, which can directly address the effects of explicit solvent, electric field, and electrode potential on reaction intermediates and transition states. We found that the couplings between CO* and NOH* and CONH* and N* are most favorable for the formation of two C–N bonds of urea, respectively. According to this mechanism, we not only reproduced the experimental Faradaic efficiencies of different products on Zn but also rationalized the activity trend of urea synthesis over a set of catalysts. More interestingly, we have revealed that adsorbed N* species on Fe and Mo have an essential promotion on urea production. Guided by the mechanistic insights, we finally proposed a compressive strain engineering to tune the d-band center of Zn, which can decrease the two C–N coupling barriers to 0.06 and 0 eV, respectively, and deliver a remarkable urea Faradaic efficiency (FE) of 88.5% using CO and NO as reactants.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":null,"pages":null},"PeriodicalIF":12.9,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142246916","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 : 2024-09-17DOI: 10.1021/acscatal.4c04457
Qi Cui, Pan Zhang, Bing-Wen Li, Yi Jin, Qianwei Zhang, Hong-Xi Bai, Zhi-Xiang Yu
Developing reactions to synthesize challenging eight-membered carbocycles is a research frontier of organic synthesis. Reported here is the development of Rh-catalyzed [5 + 1 + 2] cycloaddition of yne-3-acyloxy-1,4-enynes (Yne-ACEs, shortened as YACEs) and CO, in which sequentially five-carbon (generated from 3-acyloxy-1,4-enynes), one-carbon (CO), and two-carbon (alkynes) units are assembled into the final 5/8 scaffold containing a cyclooctatrienone structure. This reaction has a broad scope and can be carried out under mild conditions. Keys to the success of the present [5 + 1 + 2] reaction, discovered and supported by experiments and ab initio calculations, include using terminal alkyne in the 3-acyloxy-1,4-enyne moiety of the substrates so that 1,2-acyloxy migration (instead of 1,3-acyloxy migration, a step required for a competing [4 + 2 + 1] reaction) can be realized and applying an electron-rich aryl group (here, it is p-dimethylamino phenyl) in the acyloxy group to make a [5 + 1] pathway disfavored. Quantum chemical calculations have also been used to answer why this reaction is [5 + 1 + 2] but not [5 + 2 + 1] (where alkyne insertion is ahead of CO insertion) and to find the factors disfavoring the competitive [5 + 2], [5 + 1], and [4 + 2 + 1] reactions.
{"title":"Rhodium-Catalyzed [5 + 1 + 2] Cycloaddition of Yne-3-acyloxy-1,4-enynes (YACEs) and Carbon Monoxide: Reaction Development and Mechanism","authors":"Qi Cui, Pan Zhang, Bing-Wen Li, Yi Jin, Qianwei Zhang, Hong-Xi Bai, Zhi-Xiang Yu","doi":"10.1021/acscatal.4c04457","DOIUrl":"https://doi.org/10.1021/acscatal.4c04457","url":null,"abstract":"Developing reactions to synthesize challenging eight-membered carbocycles is a research frontier of organic synthesis. Reported here is the development of Rh-catalyzed [5 + 1 + 2] cycloaddition of yne-3-acyloxy-1,4-enynes (Yne-ACEs, shortened as YACEs) and CO, in which sequentially five-carbon (generated from 3-acyloxy-1,4-enynes), one-carbon (CO), and two-carbon (alkynes) units are assembled into the final 5/8 scaffold containing a cyclooctatrienone structure. This reaction has a broad scope and can be carried out under mild conditions. Keys to the success of the present [5 + 1 + 2] reaction, discovered and supported by experiments and <i>ab initio</i> calculations, include using terminal alkyne in the 3-acyloxy-1,4-enyne moiety of the substrates so that 1,2-acyloxy migration (instead of 1,3-acyloxy migration, a step required for a competing [4 + 2 + 1] reaction) can be realized and applying an electron-rich aryl group (here, it is <i>p</i>-dimethylamino phenyl) in the acyloxy group to make a [5 + 1] pathway disfavored. Quantum chemical calculations have also been used to answer why this reaction is [5 + 1 + 2] but not [5 + 2 + 1] (where alkyne insertion is ahead of CO insertion) and to find the factors disfavoring the competitive [5 + 2], [5 + 1], and [4 + 2 + 1] reactions.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":null,"pages":null},"PeriodicalIF":12.9,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142235403","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 : 2024-09-17DOI: 10.1021/acscatal.4c04048
Xiusong Huang, Junjie Xu, Xuefei Xu, Shujuan Wang
A near-neutral HER process suffers from sluggish kinetics. Many efforts have been focused on the design of advanced electrocatalysts. However, the field of electrolyte engineering has rarely been investigated. Considering the complicated ion composition of electrolytes in a near-neutral environment, this work investigated the HER performance of several buffer electrolytes composed of different charged hydrogen sources. The results indicated that a positively charged hydrogen source, namely, NH4+, possessed a superior HER performance to other buffer electrolytes. Under the condition of high concentration, Tafel slopes at 10 and 31 mA·cm–2 were 61 and 84 mV·dec–1, respectively, on the Pt/C catalyst. At an overpotential of 530 mV, the current density of the NH4+ electrolyte was 1000 mA·cm–2 in contrast to only 240 mA·cm–2 for the phosphate buffer solution (PBS) electrolyte. Furthermore, to take a deep perspective into the HER mechanism under a near-neutral environment, based on the experimental values and grand canonical DFT, this work designed a two-step thermodynamic circle to calculate the formation energy of ionic hydrogen sources needed to be transferred from a bulk electrolyte solution to the vicinity of a charged electrode. The result clearly demonstrated that the negatively charged hydrogen sources could not spontaneously approach the Pt electrode surface under certain cathode overpotentials. This work further implemented ab initio molecule dynamics (AIMD) to investigate solvated NH4+ and found that the desolvation process was facilitated by the cathode potential. The proton dissociation process was studied through constrained AIMD. The results clearly showed that the proton dissociated from NH4+ would be directly transferred to the electrode surface, while the proton dissociated from other hydrogen sources would be captured by a hydrogen bond network of water. This discrepancy demonstrated a possibility that NH4+ could directly participate in HER under a near-neutral environment or that the proton dissociation efficiency of NH4+ near the cathode was superior to other hydrogen sources.
{"title":"Improved Near-Neutral Hydrogen Evolution Reaction Kinetics through Electrolyte Engineering with the Efficient Hydrogen Source NH4+","authors":"Xiusong Huang, Junjie Xu, Xuefei Xu, Shujuan Wang","doi":"10.1021/acscatal.4c04048","DOIUrl":"https://doi.org/10.1021/acscatal.4c04048","url":null,"abstract":"A near-neutral HER process suffers from sluggish kinetics. Many efforts have been focused on the design of advanced electrocatalysts. However, the field of electrolyte engineering has rarely been investigated. Considering the complicated ion composition of electrolytes in a near-neutral environment, this work investigated the HER performance of several buffer electrolytes composed of different charged hydrogen sources. The results indicated that a positively charged hydrogen source, namely, NH<sub>4</sub><sup>+</sup>, possessed a superior HER performance to other buffer electrolytes. Under the condition of high concentration, Tafel slopes at 10 and 31 mA·cm<sup>–2</sup> were 61 and 84 mV·dec<sup>–1</sup>, respectively, on the Pt/C catalyst. At an overpotential of 530 mV, the current density of the NH<sub>4</sub><sup>+</sup> electrolyte was 1000 mA·cm<sup>–2</sup> in contrast to only 240 mA·cm<sup>–2</sup> for the phosphate buffer solution (PBS) electrolyte. Furthermore, to take a deep perspective into the HER mechanism under a near-neutral environment, based on the experimental values and grand canonical DFT, this work designed a two-step thermodynamic circle to calculate the formation energy of ionic hydrogen sources needed to be transferred from a bulk electrolyte solution to the vicinity of a charged electrode. The result clearly demonstrated that the negatively charged hydrogen sources could not spontaneously approach the Pt electrode surface under certain cathode overpotentials. This work further implemented ab initio molecule dynamics (AIMD) to investigate solvated NH<sub>4</sub><sup>+</sup> and found that the desolvation process was facilitated by the cathode potential. The proton dissociation process was studied through constrained AIMD. The results clearly showed that the proton dissociated from NH<sub>4</sub><sup>+</sup> would be directly transferred to the electrode surface, while the proton dissociated from other hydrogen sources would be captured by a hydrogen bond network of water. This discrepancy demonstrated a possibility that NH<sub>4</sub><sup>+</sup> could directly participate in HER under a near-neutral environment or that the proton dissociation efficiency of NH<sub>4</sub><sup>+</sup> near the cathode was superior to other hydrogen sources.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":null,"pages":null},"PeriodicalIF":12.9,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142237063","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 : 2024-09-17DOI: 10.1021/acscatal.4c04510
Alan Carletti, Florian Csarman, Marco Sola, Gianantonio Battistuzzi, Roland Ludwig, Giulia Di Rocco
Lytic polysaccharide monooxygenases (LPMOs) are copper enzymes discovered in the past decade. Their importance in the degradation of recalcitrant substrates in sustainable processes is now well established; however, the catalytic peroxygenase mechanism has yet to be fully understood. This is also because the study of reaction kinetics has to deal with multiple variables, including the nature of the substrates, the presence of unwanted side reactions, and the low protein stability in the presence of H2O2 as the cosubstrate. In this work, three bacterial LPMOs from the AA10 family were investigated: Pseudomonas putida AA10 (PpAA10), Streptomyces coelicolor AA10B (ScAA10B), and AA10C (ScAA10C). Their activity against specific substrates was initially evaluated by ATR-FTIR for a qualitative characterization, and then, to determine electrochemically their kinetic constants, an amperometric assay based on the detection of the H2O2 consumption was used. This allowed the determination of turnover numbers (TNs) and total turnover numbers (TTNs) on different substrates. The best performance was obtained with ScAA10C and ScAAA10B on nanocrystalline cellulose with TNs of 3.81 and 2.88 s–1, respectively, and TTNs of 1208 and 735, respectively. PpAA10 is active on β-chitin with a TN of 1.02 s–1 and a TTN of 61, providing valuable insight into their substrate specificity and stability. Although the initial rates were found to be lower than those for fungal LPMOs, the enzyme stability over time increased on more crystalline substrates and in the presence of the carbohydrate-binding module (CBM), yielding activity values comparable to those for fungal LPMOs. Moreover, the presence of the CBM resulted in a more efficient consumption of H2O2 by LPMO, leading to improved enzymatic activity and increased resistance to oxidative inactivation.
{"title":"Kinetic and Substrate Specificity Determination of Bacterial LPMOs","authors":"Alan Carletti, Florian Csarman, Marco Sola, Gianantonio Battistuzzi, Roland Ludwig, Giulia Di Rocco","doi":"10.1021/acscatal.4c04510","DOIUrl":"https://doi.org/10.1021/acscatal.4c04510","url":null,"abstract":"Lytic polysaccharide monooxygenases (LPMOs) are copper enzymes discovered in the past decade. Their importance in the degradation of recalcitrant substrates in sustainable processes is now well established; however, the catalytic peroxygenase mechanism has yet to be fully understood. This is also because the study of reaction kinetics has to deal with multiple variables, including the nature of the substrates, the presence of unwanted side reactions, and the low protein stability in the presence of H<sub>2</sub>O<sub>2</sub> as the cosubstrate. In this work, three bacterial LPMOs from the AA10 family were investigated: <i>Pseudomonas putida</i> AA10 (<i>Pp</i>AA10), <i>Streptomyces coelicolor</i> AA10B (<i>Sc</i>AA10B), and AA10C (<i>Sc</i>AA10C). Their activity against specific substrates was initially evaluated by ATR-FTIR for a qualitative characterization, and then, to determine electrochemically their kinetic constants, an amperometric assay based on the detection of the H<sub>2</sub>O<sub>2</sub> consumption was used. This allowed the determination of turnover numbers (TNs) and total turnover numbers (TTNs) on different substrates. The best performance was obtained with ScAA10C and ScAAA10B on nanocrystalline cellulose with TNs of 3.81 and 2.88 s<sup>–1</sup>, respectively, and TTNs of 1208 and 735, respectively. PpAA10 is active on β-chitin with a TN of 1.02 s<sup>–1</sup> and a TTN of 61, providing valuable insight into their substrate specificity and stability. Although the initial rates were found to be lower than those for fungal LPMOs, the enzyme stability over time increased on more crystalline substrates and in the presence of the carbohydrate-binding module (CBM), yielding activity values comparable to those for fungal LPMOs. Moreover, the presence of the CBM resulted in a more efficient consumption of H<sub>2</sub>O<sub>2</sub> by LPMO, leading to improved enzymatic activity and increased resistance to oxidative inactivation.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":null,"pages":null},"PeriodicalIF":12.9,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142235368","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 : 2024-09-17DOI: 10.1021/acscatal.4c04321
Thomas M. Groseclose, Erin A. Kober, Matilda Clark, Benjamin Moore, Shounak Banerjee, Victoria Bemmer, Gregg T. Beckham, Andrew R. Pickford, Taraka T. Dale, Hau B. Nguyen
The ability of enzymes to hydrolyze the ubiquitous polyester, poly(ethylene terephthalate) (PET), has enabled the potential for bioindustrial recycling of this waste plastic. To date, many of these PET hydrolases have been engineered for improved catalytic activity and stability, but current screening methods have limitations in screening large libraries, including under high-temperature conditions. Here, we developed a platform that can simultaneously interrogate PET hydrolase libraries of 104–105 variants (per round) for protein solubility, thermostability, and activity via paired, plate-based split green fluorescent protein and model substrate screens. We then applied this platform to improve the performance of a benchmark PET hydrolase, leaf-branch compost cutinase, by directed evolution. Our engineered enzyme exhibited higher catalytic activity relative to the benchmark, LCC-ICCG, on amorphous PET film coupon substrates (∼9.4% crystallinity) in pH-controlled bioreactors at both 65 °C (8.5% higher conversion at 48 h and 38% higher maximum rate, at 2.9% substrate loading) and 68 °C (11.2% higher conversion at 48 h and 43% higher maximum rate, at 16.5% substrate loading), up to 48 h, highlighting the potential of this screening platform to accelerate enzyme development for PET recycling.
{"title":"A High-Throughput Screening Platform for Engineering Poly(ethylene Terephthalate) Hydrolases","authors":"Thomas M. Groseclose, Erin A. Kober, Matilda Clark, Benjamin Moore, Shounak Banerjee, Victoria Bemmer, Gregg T. Beckham, Andrew R. Pickford, Taraka T. Dale, Hau B. Nguyen","doi":"10.1021/acscatal.4c04321","DOIUrl":"https://doi.org/10.1021/acscatal.4c04321","url":null,"abstract":"The ability of enzymes to hydrolyze the ubiquitous polyester, poly(ethylene terephthalate) (PET), has enabled the potential for bioindustrial recycling of this waste plastic. To date, many of these PET hydrolases have been engineered for improved catalytic activity and stability, but current screening methods have limitations in screening large libraries, including under high-temperature conditions. Here, we developed a platform that can simultaneously interrogate PET hydrolase libraries of 10<sup>4</sup>–10<sup>5</sup> variants (per round) for protein solubility, thermostability, and activity via paired, plate-based split green fluorescent protein and model substrate screens. We then applied this platform to improve the performance of a benchmark PET hydrolase, leaf-branch compost cutinase, by directed evolution. Our engineered enzyme exhibited higher catalytic activity relative to the benchmark, LCC-ICCG, on amorphous PET film coupon substrates (∼9.4% crystallinity) in pH-controlled bioreactors at both 65 °C (8.5% higher conversion at 48 h and 38% higher maximum rate, at 2.9% substrate loading) and 68 °C (11.2% higher conversion at 48 h and 43% higher maximum rate, at 16.5% substrate loading), up to 48 h, highlighting the potential of this screening platform to accelerate enzyme development for PET recycling.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":null,"pages":null},"PeriodicalIF":12.9,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142235367","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 : 2024-09-16DOI: 10.1021/acscatal.4c03431
Tong Hu, Xiaodi Cheng, Jie Luo, Yupeng Yan, Qin Zhang, Yang Li
Artificial photocatalytic nitrogen reduction to ammonia (NH3) driven by solar energy provides a feasible NH3 production strategy with environmentally sustainable and low energy consumption. However, activating inert nitrogen molecules (N2) with high bond energy remains a challenge for the photocatalytic nitrogen reduction reaction (PCNRR). As important components of natural nitrogenase, Fe species have received extensive attention in view of their capacity to weaken the strong N≡N triple bond. By modifying their local electron density, Fe species cause the adsorbed N2 to shift from polar to nonpolar, lowering N2 stability. Among many photocatalysts, Fe-based photocatalysts have been widely applied as nitrogen fixation materials. In this paper, the latest research progress on Fe-based photocatalysts for PCNRR is reviewed. The basic principle and reaction pathway of PCNRR are presented initially. The determination methods for product ammonia, as well as their benefits and drawbacks, are listed. Subsequently, the applications of Fe-based materials in PCNRR are systematically reviewed from the single-atom Fe, Fe-based metal organic frameworks, iron oxides, and Fe/other atoms codoping. Then, the unique advantages of different types of Fe-based nitrogen fixation photocatalysts are summarized. The authenticity verification of the PCNRR performance is briefly introduced. Finally, the main challenges encountered in the realm of PCNRR are also explored, along with the future prospects. This review aims to present useful guidance for the design of Fe-based nitrogen fixation photocatalysts with high activity, stability, and selectivity.
{"title":"Fe-Based Materials for Photocatalytic Nitrogen Reduction to Ammonia: Unique Advantages, Challenges, and Perspectives","authors":"Tong Hu, Xiaodi Cheng, Jie Luo, Yupeng Yan, Qin Zhang, Yang Li","doi":"10.1021/acscatal.4c03431","DOIUrl":"https://doi.org/10.1021/acscatal.4c03431","url":null,"abstract":"Artificial photocatalytic nitrogen reduction to ammonia (NH<sub>3</sub>) driven by solar energy provides a feasible NH<sub>3</sub> production strategy with environmentally sustainable and low energy consumption. However, activating inert nitrogen molecules (N<sub>2</sub>) with high bond energy remains a challenge for the photocatalytic nitrogen reduction reaction (PCNRR). As important components of natural nitrogenase, Fe species have received extensive attention in view of their capacity to weaken the strong N≡N triple bond. By modifying their local electron density, Fe species cause the adsorbed N<sub>2</sub> to shift from polar to nonpolar, lowering N<sub>2</sub> stability. Among many photocatalysts, Fe-based photocatalysts have been widely applied as nitrogen fixation materials. In this paper, the latest research progress on Fe-based photocatalysts for PCNRR is reviewed. The basic principle and reaction pathway of PCNRR are presented initially. The determination methods for product ammonia, as well as their benefits and drawbacks, are listed. Subsequently, the applications of Fe-based materials in PCNRR are systematically reviewed from the single-atom Fe, Fe-based metal organic frameworks, iron oxides, and Fe/other atoms codoping. Then, the unique advantages of different types of Fe-based nitrogen fixation photocatalysts are summarized. The authenticity verification of the PCNRR performance is briefly introduced. Finally, the main challenges encountered in the realm of PCNRR are also explored, along with the future prospects. This review aims to present useful guidance for the design of Fe-based nitrogen fixation photocatalysts with high activity, stability, and selectivity.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":null,"pages":null},"PeriodicalIF":12.9,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142234420","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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