Pub Date : 2025-12-07DOI: 10.1021/acscatal.5c07156
Marcus Yu, Wenjie Liao, Yong Yuan, Jiahua Zhou, Ping Liu, Jingguang G. Chen
Transition metal nitrides (TMNs) have been explored as effective supports for Pt due to their Pt-like electronic properties. However, there is a lack of fundamental understanding regarding the behavior of Pt on different TMNs (Pt/TMN). Herein two TMNs, Mo2N and TiN, were modified with Pt and compared using methanol decomposition as a probe reaction via both ultrahigh vacuum (UHV) studies on thin films and ambient-pressure batch reactor studies of powder catalysts. Temperature-programmed desorption (TPD) and high-resolution electron energy loss spectroscopy (HREELS) measurements were conducted under UHV conditions with Mo2N and TiN thin films. Mo2N was shown to favor C–H bond scission to form CO with a 56.2% selectivity, while TiN favored C–O bond scission to form CH4 with a 74.5% selectivity. The addition of 0.9 monolayers (MLs) of Pt increased C–H bond scission selectivity to 89.7% and 49.2% for Mo2N and TiN respectively. Density functional theory (DFT) calculations on model surfaces revealed that the binding energy of O (BE*O) was significantly reduced on Pt/TMNs, from −4.02 eV on Mo2N to −1.31 eV on Pt/Mo2N and −4.74 eV on TiN to −1.37 eV on Pt/TiN. As a result, C–O bond scission pathways were suppressed, leading to the preferential C–H bond scission that was observed experimentally. The C–O and C–H bond scission trends observed on thin films were then extended to powder catalysts, which demonstrated similar trends toward methanol decomposition. Results from the current study establish that by combining UHV studies and DFT calculations over model surfaces, one can effectively predict the catalytic behavior of realistic TMN powder catalysts.
{"title":"Controlling Selective C–O and C–H Bond Scission of Methanol by Supporting Pt on TiN and Mo2N Model Surfaces and Powder Catalysts","authors":"Marcus Yu, Wenjie Liao, Yong Yuan, Jiahua Zhou, Ping Liu, Jingguang G. Chen","doi":"10.1021/acscatal.5c07156","DOIUrl":"https://doi.org/10.1021/acscatal.5c07156","url":null,"abstract":"Transition metal nitrides (TMNs) have been explored as effective supports for Pt due to their Pt-like electronic properties. However, there is a lack of fundamental understanding regarding the behavior of Pt on different TMNs (Pt/TMN). Herein two TMNs, Mo<sub>2</sub>N and TiN, were modified with Pt and compared using methanol decomposition as a probe reaction via both ultrahigh vacuum (UHV) studies on thin films and ambient-pressure batch reactor studies of powder catalysts. Temperature-programmed desorption (TPD) and high-resolution electron energy loss spectroscopy (HREELS) measurements were conducted under UHV conditions with Mo<sub>2</sub>N and TiN thin films. Mo<sub>2</sub>N was shown to favor C–H bond scission to form CO with a 56.2% selectivity, while TiN favored C–O bond scission to form CH<sub>4</sub> with a 74.5% selectivity. The addition of 0.9 monolayers (MLs) of Pt increased C–H bond scission selectivity to 89.7% and 49.2% for Mo<sub>2</sub>N and TiN respectively. Density functional theory (DFT) calculations on model surfaces revealed that the binding energy of O (BE<sub>*O</sub>) was significantly reduced on Pt/TMNs, from −4.02 eV on Mo<sub>2</sub>N to −1.31 eV on Pt/Mo<sub>2</sub>N and −4.74 eV on TiN to −1.37 eV on Pt/TiN. As a result, C–O bond scission pathways were suppressed, leading to the preferential C–H bond scission that was observed experimentally. The C–O and C–H bond scission trends observed on thin films were then extended to powder catalysts, which demonstrated similar trends toward methanol decomposition. Results from the current study establish that by combining UHV studies and DFT calculations over model surfaces, one can effectively predict the catalytic behavior of realistic TMN powder catalysts.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"93 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145703820","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-07DOI: 10.1021/acscatal.5c07296
Mahdi Hosseinpour, Thomas F. Winterstein, Clivia Hejny, Marc Heggen, Bernhard Klötzer, Simon Penner
We explore the fundamental pathways of carbon formation and regeneration in a model Pd/Zr catalyst during dry reforming of methane (DRM) and under related reaction conditions. Using a combination of XPS, SEM, and EDX, we track the structural and chemical changes of the catalyst throughout the reaction, deactivation, and regeneration cycles. By systematically adjusting feed composition, CO2 conversion, and regeneration atmospheres, the study identifies how different gas-phase species contribute to carbon formation and clean-off. It also determines the conditions that influence the accessibility of the reactive metal–oxide interfaces. A comparison with the analogous Ni/Zr system highlights how the choice of the metal affects regeneration chemistry and the importance of accessible metal oxide phase boundaries in CO2 activation. The experimental setup combines temperature-resolved reaction profiling with micro- and spectroscopic surface characterization at key intermediate stages, enabling direct links among catalytic activity, surface morphology, and regeneration results. This approach offers insights into how catalyst design, operational conditions, and regeneration methods can be optimized to achieve high DRM activity and effective carbon management in noble metal–oxide systems.
{"title":"To Coke or Not to Coke: When Pd Is Not Noble Anymore under Methane Dry Reforming Conditions","authors":"Mahdi Hosseinpour, Thomas F. Winterstein, Clivia Hejny, Marc Heggen, Bernhard Klötzer, Simon Penner","doi":"10.1021/acscatal.5c07296","DOIUrl":"https://doi.org/10.1021/acscatal.5c07296","url":null,"abstract":"We explore the fundamental pathways of carbon formation and regeneration in a model Pd/Zr catalyst during dry reforming of methane (DRM) and under related reaction conditions. Using a combination of XPS, SEM, and EDX, we track the structural and chemical changes of the catalyst throughout the reaction, deactivation, and regeneration cycles. By systematically adjusting feed composition, CO<sub>2</sub> conversion, and regeneration atmospheres, the study identifies how different gas-phase species contribute to carbon formation and clean-off. It also determines the conditions that influence the accessibility of the reactive metal–oxide interfaces. A comparison with the analogous Ni/Zr system highlights how the choice of the metal affects regeneration chemistry and the importance of accessible metal oxide phase boundaries in CO<sub>2</sub> activation. The experimental setup combines temperature-resolved reaction profiling with micro- and spectroscopic surface characterization at key intermediate stages, enabling direct links among catalytic activity, surface morphology, and regeneration results. This approach offers insights into how catalyst design, operational conditions, and regeneration methods can be optimized to achieve high DRM activity and effective carbon management in noble metal–oxide systems.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"6 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145703821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-06DOI: 10.1021/acscatal.5c06271
Wang Xu, Yuhuang Huang, Zhuohan Lin, Qiaohui Ruan, PeiQing Yuan, Yan Li
Efficient zeolitic recycling of polyolefin waste into C2–C4 light olefins offers an attractive route toward resource recovery; however, conventional zeolite catalysts suffer from severe mass transport limitations that lead to undesired secondary reactions and coke formation. Here, we report a “structure modulation and intelligent optimization” strategy to develop hierarchical ZSM-5 (H-ZSM-5), integrating tailored mesoporosity and crystal size control via Bayesian optimization (BO). Catalytic performance was evaluated in a two-stage system combining thermal pyrolysis and subsequent catalytic cracking. BO efficiently navigates this multivariate design space, identifying an optimal architecture (∼100 nm crystals, 4.0 nm mesopores) that achieved 92.6 wt % total gas yield and 85.1 wt % light olefin selectivity at 500 °C with a low catalyst-to-feed ratio (0.2). The nanoscale H-ZSM-5 also exhibited durability over 40 consecutive cycles and broad compatibility with postconsumer plastic mixtures. Mechanistic studies revealed that the synergy between nanoscale morphology and hierarchical porosity enhances mass transport and acid site accessibility, demonstrating that complex catalyst architectures can be precisely optimized via artificial intelligence strategies, such as BO.
{"title":"Bayesian Optimization of Hierarchical ZSM-5 for High-Efficiency Polyolefin Waste Recycling to Light Olefins","authors":"Wang Xu, Yuhuang Huang, Zhuohan Lin, Qiaohui Ruan, PeiQing Yuan, Yan Li","doi":"10.1021/acscatal.5c06271","DOIUrl":"https://doi.org/10.1021/acscatal.5c06271","url":null,"abstract":"Efficient zeolitic recycling of polyolefin waste into C<sub>2</sub>–C<sub>4</sub> light olefins offers an attractive route toward resource recovery; however, conventional zeolite catalysts suffer from severe mass transport limitations that lead to undesired secondary reactions and coke formation. Here, we report a “structure modulation and intelligent optimization” strategy to develop hierarchical ZSM-5 (H-ZSM-5), integrating tailored mesoporosity and crystal size control via Bayesian optimization (BO). Catalytic performance was evaluated in a two-stage system combining thermal pyrolysis and subsequent catalytic cracking. BO efficiently navigates this multivariate design space, identifying an optimal architecture (∼100 nm crystals, 4.0 nm mesopores) that achieved 92.6 wt % total gas yield and 85.1 wt % light olefin selectivity at 500 °C with a low catalyst-to-feed ratio (0.2). The nanoscale H-ZSM-5 also exhibited durability over 40 consecutive cycles and broad compatibility with postconsumer plastic mixtures. Mechanistic studies revealed that the synergy between nanoscale morphology and hierarchical porosity enhances mass transport and acid site accessibility, demonstrating that complex catalyst architectures can be precisely optimized via artificial intelligence strategies, such as BO.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"242 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145690043","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}
Photocatalytic oxidative dehydrogenation of ethane (ODHE) offers a promising strategy for ethylene production under mild conditions. However, achieving a high ethylene yield and selectivity remains challenging due to the high activation barrier of ethane C–H bonds and the propensity for overoxidation to CO2. Herein, we demonstrate that Pd/TiO2-6, a palladium-decorated, 6 nm-sized TiO2 support, functions as a selective photocatalyst for ODHE using O2 under continuous-flow conditions. The optimized Pd/TiO2-6 catalyst exhibits an ethylene production rate of 69.9 mmol g–1 h–1 with 78.9% selectivity and a high apparent quantum efficiency of 17.9%. It also demonstrates robust stability over 45 h of continuous operation, outperforming most reported photo- and thermocatalysts. In situ and time-resolved characterizations revealed that the highly dispersed, oxidized Pd species serve as essential mediators in promoting charge separation and enabling moderate oxygen activation. This synergistic effect enables the selective activation of C2H6 to form key *C2H4 intermediates, ultimately leading to a high ethylene formation rate. This work reveals key insights into preparing highly efficient ODHE photocatalysts by harnessing the support size effect.
{"title":"Size-Engineered Highly Active and Stable Pd/TiO2 Photocatalysts for Selective Oxidative Dehydrogenation of Ethane","authors":"Yachao Wang, Yanqing Jiao, Shufen Ma, Yaxiong Wei, Weixin Huang, Cong Fu","doi":"10.1021/acscatal.5c06445","DOIUrl":"https://doi.org/10.1021/acscatal.5c06445","url":null,"abstract":"Photocatalytic oxidative dehydrogenation of ethane (ODHE) offers a promising strategy for ethylene production under mild conditions. However, achieving a high ethylene yield and selectivity remains challenging due to the high activation barrier of ethane C–H bonds and the propensity for overoxidation to CO<sub>2</sub>. Herein, we demonstrate that Pd/TiO<sub>2</sub>-6, a palladium-decorated, 6 nm-sized TiO<sub>2</sub> support, functions as a selective photocatalyst for ODHE using O<sub>2</sub> under continuous-flow conditions. The optimized Pd/TiO<sub>2</sub>-6 catalyst exhibits an ethylene production rate of 69.9 mmol g<sup>–1</sup> h<sup>–1</sup> with 78.9% selectivity and a high apparent quantum efficiency of 17.9%. It also demonstrates robust stability over 45 h of continuous operation, outperforming most reported photo- and thermocatalysts. <i>In situ</i> and time-resolved characterizations revealed that the highly dispersed, oxidized Pd species serve as essential mediators in promoting charge separation and enabling moderate oxygen activation. This synergistic effect enables the selective activation of C<sub>2</sub>H<sub>6</sub> to form key *C<sub>2</sub>H<sub>4</sub> intermediates, ultimately leading to a high ethylene formation rate. This work reveals key insights into preparing highly efficient ODHE photocatalysts by harnessing the support size effect.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"31 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145690081","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-06DOI: 10.1021/acscatal.5c06462
Dongrui Hou, Li Han, Ziyue Hou, Zirui Yang, Tianliang Lu, Xiaoqin Si, Xin liu, Jinrong Li, Wenbo Luo, Jianfeng Wang
Oxygen vacancies (OVs) play a crucial role in photocatalytic nitrogen fixation, yet current studies predominantly focus on preconstructed OVs (PC-OVs), with limited attention given to photoexcitation-induced OVs (PE-OVs). In this work, Sn-doped BiOCl-VO (Sn-BOC-VO) was synthesized via a facile one-pot hydrothermal method to actively generate PE-OVs. EPR analysis confirmed that Sn doping promotes the formation of PE-OVs. Quasi in situ XPS revealed that light irradiation further enhances OVs generation in Sn-BOC-VO and induces electron transfer from the O and Bi to the Sn. Photoelectrochemical tests demonstrated that Sn-BOC-VO improves visible-light absorption, facilitates charge separation, and suppresses carrier recombination, collectively leading to a 16.8-fold increase in the nitrogen fixation rate compared to BOC-VO. In situ DRIFTS spectroscopy tracked key reaction intermediates, while DFT calculations indicated electron transfer from Sn-BOC-VO to adsorbed N2, highlighting the synergy between Sn and OVs in promoting N2 activation and improving the photocatalytic nitrogen reduction reaction (pNRR) efficiency. Importantly, Sn-BOC-VO exhibits a reduced energy barrier of 1.81 eV for the rate-determining step, which is significantly lower than that of BOC-VO (2.22 eV), underscoring the critical role of Sn in optimizing reaction kinetics. This study offers insights into the design of photoexcited OV-active sites and emphasizes the dynamic role of OVs in catalytic reactions.
{"title":"Dynamic Oxygen Vacancy Formation via Photoexcitation in Sn-Modified Defective BiOCl Nanoflowers for Enhanced Photocatalytic Nitrogen Fixation","authors":"Dongrui Hou, Li Han, Ziyue Hou, Zirui Yang, Tianliang Lu, Xiaoqin Si, Xin liu, Jinrong Li, Wenbo Luo, Jianfeng Wang","doi":"10.1021/acscatal.5c06462","DOIUrl":"https://doi.org/10.1021/acscatal.5c06462","url":null,"abstract":"Oxygen vacancies (OVs) play a crucial role in photocatalytic nitrogen fixation, yet current studies predominantly focus on preconstructed OVs (PC-OVs), with limited attention given to photoexcitation-induced OVs (PE-OVs). In this work, Sn-doped BiOCl-V<sub>O</sub> (Sn-BOC-V<sub>O</sub>) was synthesized via a facile one-pot hydrothermal method to actively generate PE-OVs. EPR analysis confirmed that Sn doping promotes the formation of PE-OVs. Quasi in situ XPS revealed that light irradiation further enhances OVs generation in Sn-BOC-V<sub>O</sub> and induces electron transfer from the O and Bi to the Sn. Photoelectrochemical tests demonstrated that Sn-BOC-V<sub>O</sub> improves visible-light absorption, facilitates charge separation, and suppresses carrier recombination, collectively leading to a 16.8-fold increase in the nitrogen fixation rate compared to BOC-V<sub>O</sub>. In situ DRIFTS spectroscopy tracked key reaction intermediates, while DFT calculations indicated electron transfer from Sn-BOC-V<sub>O</sub> to adsorbed N<sub>2</sub>, highlighting the synergy between Sn and OVs in promoting N<sub>2</sub> activation and improving the photocatalytic nitrogen reduction reaction (pNRR) efficiency. Importantly, Sn-BOC-V<sub>O</sub> exhibits a reduced energy barrier of 1.81 eV for the rate-determining step, which is significantly lower than that of BOC-V<sub>O</sub> (2.22 eV), underscoring the critical role of Sn in optimizing reaction kinetics. This study offers insights into the design of photoexcited OV-active sites and emphasizes the dynamic role of OVs in catalytic reactions.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"1 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145690044","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-05DOI: 10.1021/acscatal.5c06687
Haruka Yamamoto, Toshiya Tanaka, Masahito Oura, Kelly M. Kopera, Megumi Okazaki, Ken Onda, Thomas E. Mallouk, Kazuhiko Maeda
An Os(II) polypyridyl complex was applied as a photosensitizer in dye-sensitized photocatalyst systems based on Pt-intercalated HCa2Nb3O10 and Pt-loaded TiO2. The Os(II) complex exhibits a spin-forbidden but partially allowed triplet metal-to-ligand charge transfer (3MLCT) transition, enabling broad visible light absorption up to 800 nm, which surpasses that of conventional Ru(II)-based dyes. Despite its shorter excited-state lifetime compared to Ru(II) complexes, efficient electron injection from the excited Os(II) dye into the semiconductor was confirmed. Under visible-light irradiation, the Os(II)-sensitized photocatalysts showed higher H2 evolution activity than the Ru(II)-sensitized photocatalysts when sodium ascorbate was used as an electron donor, demonstrating effective utilization of long-wavelength visible light. In contrast, negligible H2 evolution was observed when NaI was employed as a redox mediator for Z-scheme water splitting. Transient absorption spectroscopy revealed that the lack of activity stemmed from inefficient electron transfer from I– to oxidized Os(II). These findings highlight the importance of selecting appropriate redox mediators to fully exploit long-wavelength dyes for overall water splitting under visible light.
{"title":"Charge Transfer Dynamics in Dye-Sensitized Photocatalysts Using Metal Complex Sensitizers with Long-Wavelength Visible Light Absorption Based on Singlet–Triplet Excitation","authors":"Haruka Yamamoto, Toshiya Tanaka, Masahito Oura, Kelly M. Kopera, Megumi Okazaki, Ken Onda, Thomas E. Mallouk, Kazuhiko Maeda","doi":"10.1021/acscatal.5c06687","DOIUrl":"https://doi.org/10.1021/acscatal.5c06687","url":null,"abstract":"An Os(II) polypyridyl complex was applied as a photosensitizer in dye-sensitized photocatalyst systems based on Pt-intercalated HCa<sub>2</sub>Nb<sub>3</sub>O<sub>10</sub> and Pt-loaded TiO<sub>2</sub>. The Os(II) complex exhibits a spin-forbidden but partially allowed triplet metal-to-ligand charge transfer (<sup>3</sup>MLCT) transition, enabling broad visible light absorption up to 800 nm, which surpasses that of conventional Ru(II)-based dyes. Despite its shorter excited-state lifetime compared to Ru(II) complexes, efficient electron injection from the excited Os(II) dye into the semiconductor was confirmed. Under visible-light irradiation, the Os(II)-sensitized photocatalysts showed higher H<sub>2</sub> evolution activity than the Ru(II)-sensitized photocatalysts when sodium ascorbate was used as an electron donor, demonstrating effective utilization of long-wavelength visible light. In contrast, negligible H<sub>2</sub> evolution was observed when NaI was employed as a redox mediator for Z-scheme water splitting. Transient absorption spectroscopy revealed that the lack of activity stemmed from inefficient electron transfer from I<sup>–</sup> to oxidized Os(II). These findings highlight the importance of selecting appropriate redox mediators to fully exploit long-wavelength dyes for overall water splitting under visible light.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"130 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145674312","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}
Cu-exchanged zeolites are crucial catalysts for activating small molecules toward value-added or environmentally benign products. This study investigates the oxidant-driven methane conversion over Cu/CHA, with a focus on the role of oxidants (N2O vs O2) in modulating catalytic performance and reaction mechanisms. Cu/CHA zeolites were prepared by ion exchange with Cu species primarily existing as highly dispersed isolated Cu2+ ions and partially paired Cu species, as confirmed by XAFS, HAADF-STEM, and NO adsorption FTIR spectroscopy. Comparative studies revealed distinct catalytic performance depending on the oxidant. Higher CH4 conversion and CH3OH selectivity were achieved in the N2O-driven system than in the O2 case. The possible reason was attributed to the monatomic oxygen generated on Cu sites by N2O decomposition, which cleaved the C–H bond of CH4, inserted an oxygen atom, and yielded methanol. With the low risk of overoxidation, methanol would be further converted to light olefins on the acid sites at appropriate temperatures. However, O2 as the oxidant enabled the formation of aggressive peroxo (O22–) intermediates, promoting overoxidation to CO2 and limiting methanol selectivity. The choice of oxidant greatly influences the reactivity and selectivity of Cu/CHA in methane conversion. This study demonstrates that optimizing oxidant-catalyst interactions is vital for enhancing methane functionalization.
铜交换沸石是激活小分子以获得增值或环保产品的关键催化剂。本研究研究了Cu/CHA上氧化甲烷的转化，重点研究了氧化（N2O vs O2）在调节催化性能和反应机理中的作用。通过XAFS、HAADF-STEM和NO吸附FTIR光谱分析，证实了Cu/CHA沸石是通过离子交换制备的，Cu主要以高度分散的Cu2+离子和部分配对的Cu形态存在。对比研究表明，不同的氧化剂具有不同的催化性能。在n2o驱动体系中，CH4转化率和CH3OH选择性均高于O2驱动体系。原因可能是N2O分解在Cu位点上产生单原子氧，使CH4的C-H键断裂，插入一个氧原子，生成甲醇。由于过度氧化的风险低，在适当的温度下，甲醇将在酸位点进一步转化为轻烯烃。然而，O2作为氧化剂能够形成侵略性过氧化物（O22 -）中间体，促进过氧化成CO2，限制甲醇的选择性。氧化剂的选择对Cu/CHA在甲烷转化中的反应活性和选择性有很大影响。该研究表明，优化氧化剂-催化剂相互作用对提高甲烷功能化至关重要。
{"title":"The Crucial Role of Oxidants in Steering the Selective Oxidation of Methane and Subsequent Reactions on Cu/CHA Zeolites","authors":"Peipei Xiao, Lizhuo Wang, Maiko Nishibori, Kakeru Ninomiya, Jingyi Tan, Anmin Zheng, Yong Wang, Jun Huang, Toshiyuki Yokoi","doi":"10.1021/acscatal.5c06039","DOIUrl":"https://doi.org/10.1021/acscatal.5c06039","url":null,"abstract":"Cu-exchanged zeolites are crucial catalysts for activating small molecules toward value-added or environmentally benign products. This study investigates the oxidant-driven methane conversion over Cu/CHA, with a focus on the role of oxidants (N<sub>2</sub>O vs O<sub>2</sub>) in modulating catalytic performance and reaction mechanisms. Cu/CHA zeolites were prepared by ion exchange with Cu species primarily existing as highly dispersed isolated Cu<sup>2+</sup> ions and partially paired Cu species, as confirmed by XAFS, HAADF-STEM, and NO adsorption FTIR spectroscopy. Comparative studies revealed distinct catalytic performance depending on the oxidant. Higher CH<sub>4</sub> conversion and CH<sub>3</sub>OH selectivity were achieved in the N<sub>2</sub>O-driven system than in the O<sub>2</sub> case. The possible reason was attributed to the monatomic oxygen generated on Cu sites by N<sub>2</sub>O decomposition, which cleaved the C–H bond of CH<sub>4</sub>, inserted an oxygen atom, and yielded methanol. With the low risk of overoxidation, methanol would be further converted to light olefins on the acid sites at appropriate temperatures. However, O<sub>2</sub> as the oxidant enabled the formation of aggressive peroxo (O<sub>2</sub><sup>2–</sup>) intermediates, promoting overoxidation to CO<sub>2</sub> and limiting methanol selectivity. The choice of oxidant greatly influences the reactivity and selectivity of Cu/CHA in methane conversion. This study demonstrates that optimizing oxidant-catalyst interactions is vital for enhancing methane functionalization.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"159 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145674309","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 direct electrocatalytic conversion of carbon dioxide to methane using water as a medium is a reliable way to store intermittent renewable energy and solve environmental problems. However, in such multielectron/proton transfer reactions, the role of water is often overlooked. Specifically, the sluggish kinetics of water dissociation limit the effective proton supply during methane formation. Here, we propose a copper-doped CeO2 catalyst with frustrated Lewis pairs (FLPs), which can effectively reduce carbon dioxide to methane. Combined experimental analysis and theoretical calculations reveal that the synergistic interaction between Cu and FLPs forms an f-p-d gradient orbital coupling system, which significantly promotes water dissociation to generate active protons and optimizes the adsorption behavior of the *H and *COOH intermediates. Even at the large current density of −273 mA cm–2, the Faraday efficiency of Cu/CeO2-FLPs for methane was as high as 78.0%, with a conversion frequency of 15784.1 h–1 in the flow cell. This work provides a strategy for the rational design of efficient multipoint catalytic systems.
以水为介质将二氧化碳直接电催化转化为甲烷是一种可靠的储存间歇性可再生能源和解决环境问题的方法。然而，在这种多电子/质子转移反应中，水的作用往往被忽视。具体来说，缓慢的水解离动力学限制了甲烷形成过程中有效的质子供应。在这里，我们提出了一种具有受挫刘易斯对（FLPs）的铜掺杂CeO2催化剂，可以有效地将二氧化碳还原为甲烷。结合实验分析和理论计算表明，Cu与FLPs之间的协同作用形成了f-p-d梯度轨道耦合体系，显著促进了水解离生成活性质子，优化了*H和*COOH中间体的吸附行为。即使在−273 mA cm-2的大电流密度下，Cu/CeO2-FLPs对甲烷的法拉第效率也高达78.0%，在流动电池中的转换频率为15784.1 h-1。这项工作为合理设计高效的多点催化系统提供了策略。
{"title":"Constructing f-p-d Orbital Coupling Using Cu-Doped Frustrated Lewis Acid–Base Pairs in CeO2 to Boost CO2 Electroreduction","authors":"Fang Huang, Aihao Xu, Xiangyu Chen, Huanhuan Sun, Siyu He, Dong Wei, Boran Wang, Anxiang Guan, Xucai Yin, Jing Xu, Huibing He","doi":"10.1021/acscatal.5c05762","DOIUrl":"https://doi.org/10.1021/acscatal.5c05762","url":null,"abstract":"The direct electrocatalytic conversion of carbon dioxide to methane using water as a medium is a reliable way to store intermittent renewable energy and solve environmental problems. However, in such multielectron/proton transfer reactions, the role of water is often overlooked. Specifically, the sluggish kinetics of water dissociation limit the effective proton supply during methane formation. Here, we propose a copper-doped CeO<sub>2</sub> catalyst with frustrated Lewis pairs (FLPs), which can effectively reduce carbon dioxide to methane. Combined experimental analysis and theoretical calculations reveal that the synergistic interaction between Cu and FLPs forms an f-p-d gradient orbital coupling system, which significantly promotes water dissociation to generate active protons and optimizes the adsorption behavior of the *H and *COOH intermediates. Even at the large current density of −273 mA cm<sup>–<b>2</b></sup>, the Faraday efficiency of Cu/CeO<sub>2</sub>-FLPs for methane was as high as 78.0%, with a conversion frequency of 15784.1 h<sup>–1</sup> in the flow cell. This work provides a strategy for the rational design of efficient multipoint catalytic systems.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"156 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145674016","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-05DOI: 10.1021/acscatal.5c07036
Peng Liu, Jian-Rong Chen, Fei Du, Lian Duan, Wuqing Luo, Gen Chen, Xiaohe Liu, Renzhi Ma, Hongmei Li, Ting-Shan Chan, Min Liu, Ning Zhang
Bond-length of semiconductors critically influence charge distribution and orbital hybridization, potentially offering an effective route to optimize photocatalytic CO2 reduction. Conventional doping and heterostructure formation strategies frequently induce defects or band-edge shifts, thereby constraining performance and rendering direct bond-length regulation rarely concerned in semiconductor photocatalysis. In this work, we propose an in situ strategy to modulate Zn–S bond-length in hexagonal ZnS via interfacial cation engineering with Li+, Na+, K+, and Cs+ ions to fine-tune photocatalytic performance. Density functional theory (DFT) calculations predict a cation-dependent Zn–S bond contraction trend, which is experimentally verified by extended X-ray absorption fine structure spectroscopy. Photocatalytic CO2 reduction in both organic and inorganic media shows that CO evolution correlates with bond contraction, with ZnS–K+ yielding the highest CO rate (79.3 μmol·h–1·g–1) and selectivity (77.2%), outperforming most sulfide photocatalysts. In situ Fourier transform infrared spectroscopy and thermogravimetric analysis confirm that progressive Zn–S bond shortening enhances CO2 adsorption and stabilizes some key intermediates (*COOH and *CO). DFT analysis further reveals that bond contraction induces an upward shift of Zn d-band center, reducing energy barriers for intermediates conversion and promoting selective CO2-to-CO transformation. This work provides an effective strategy and mechanistic insights into cation-driven control of bond-length for photocatalytic CO2 reductions.
{"title":"Interfacial Cation-Driven Bond-Length Engineering for Selective CO2 Photoreduction to Syngas","authors":"Peng Liu, Jian-Rong Chen, Fei Du, Lian Duan, Wuqing Luo, Gen Chen, Xiaohe Liu, Renzhi Ma, Hongmei Li, Ting-Shan Chan, Min Liu, Ning Zhang","doi":"10.1021/acscatal.5c07036","DOIUrl":"https://doi.org/10.1021/acscatal.5c07036","url":null,"abstract":"Bond-length of semiconductors critically influence charge distribution and orbital hybridization, potentially offering an effective route to optimize photocatalytic CO<sub>2</sub> reduction. Conventional doping and heterostructure formation strategies frequently induce defects or band-edge shifts, thereby constraining performance and rendering direct bond-length regulation rarely concerned in semiconductor photocatalysis. In this work, we propose an in situ strategy to modulate Zn–S bond-length in hexagonal ZnS via interfacial cation engineering with Li<sup>+</sup>, Na<sup>+</sup>, K<sup>+</sup>, and Cs<sup>+</sup> ions to fine-tune photocatalytic performance. Density functional theory (DFT) calculations predict a cation-dependent Zn–S bond contraction trend, which is experimentally verified by extended X-ray absorption fine structure spectroscopy. Photocatalytic CO<sub>2</sub> reduction in both organic and inorganic media shows that CO evolution correlates with bond contraction, with ZnS–K<sup>+</sup> yielding the highest CO rate (79.3 μmol·h<sup>–1</sup>·g<sup>–1</sup>) and selectivity (77.2%), outperforming most sulfide photocatalysts. In situ Fourier transform infrared spectroscopy and thermogravimetric analysis confirm that progressive Zn–S bond shortening enhances CO<sub>2</sub> adsorption and stabilizes some key intermediates (*COOH and *CO). DFT analysis further reveals that bond contraction induces an upward shift of Zn d-band center, reducing energy barriers for intermediates conversion and promoting selective CO<sub>2</sub>-to-CO transformation. This work provides an effective strategy and mechanistic insights into cation-driven control of bond-length for photocatalytic CO<sub>2</sub> reductions.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"32 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145674037","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-05DOI: 10.1021/acscatal.5c06868
Hao Li, Jian-Wen Huang, Si Dai, Deyi Feng, Jiangli Liu, Nan Zhang, Yaojie Guo, Chun-Chi Chen, Rey-Ting Guo
The installation of halogen atoms into organic compounds through flavin-dependent halogenase (FDH)-catalyzed reactions has emerged as an attractive strategy in organic biochemistry and synthetic biology. A cyanobacterial FDH termed AetF that contains FDH and flavin reductase in the same polypeptide chain could become a useful tool enzyme as the need for including a reductase is omitted. Notably, AetF exploits a specific substrate-interaction network to consecutively brominate tryptophan (Trp) at C5 and then C7 to generate dibrominated Trp. In this study, structure-based engineering is used to eliminate the C7-halogenation capacity of AetF. The resulting variant, AetF-AIF, which contains three residue substitutions, mainly catalyzes bromination or iodination at C5 of Trp. We also show that combining AetF-AIF in tandem with wild-type AetF enables the generation of heterogeneously halogenated Trp in a one-pot reaction. The final products, 5-Br-7-I-Trp or 5-I-7-Br-Trp, depending on the order of halide addition, account for a high ratio in the reaction mixture without an additional purification step. These results demonstrate the potential of single-component Trp-FDHs for a wide range of halogenation reactions.
{"title":"Enabling Regiospecific Di-halogenation in One-Pot Reactions Using an Engineered Single-Component Flavin-Dependent Tryptophan Halogenase","authors":"Hao Li, Jian-Wen Huang, Si Dai, Deyi Feng, Jiangli Liu, Nan Zhang, Yaojie Guo, Chun-Chi Chen, Rey-Ting Guo","doi":"10.1021/acscatal.5c06868","DOIUrl":"https://doi.org/10.1021/acscatal.5c06868","url":null,"abstract":"The installation of halogen atoms into organic compounds through flavin-dependent halogenase (FDH)-catalyzed reactions has emerged as an attractive strategy in organic biochemistry and synthetic biology. A cyanobacterial FDH termed AetF that contains FDH and flavin reductase in the same polypeptide chain could become a useful tool enzyme as the need for including a reductase is omitted. Notably, AetF exploits a specific substrate-interaction network to consecutively brominate tryptophan (Trp) at C5 and then C7 to generate dibrominated Trp. In this study, structure-based engineering is used to eliminate the C7-halogenation capacity of AetF. The resulting variant, AetF-AIF, which contains three residue substitutions, mainly catalyzes bromination or iodination at C5 of Trp. We also show that combining AetF-AIF in tandem with wild-type AetF enables the generation of heterogeneously halogenated Trp in a one-pot reaction. The final products, 5-Br-7-I-Trp or 5-I-7-Br-Trp, depending on the order of halide addition, account for a high ratio in the reaction mixture without an additional purification step. These results demonstrate the potential of single-component Trp-FDHs for a wide range of halogenation reactions.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"129 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145674040","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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