ACS Catalysis Pub Date : 2025-03-21DOI: 10.1021/acscatal.4c0520810.1021/acscatal.4c05208
Areti Moutsiou, Andrea Olivati, Luis A. Cipriano, Alessandra Sivo, Sean M. Collins, Quentin M. Ramasse, Ik Seon Kwon, Giovanni Di Liberto, Mohamad Kanso, Robert Wojcieszak, Gianfranco Pacchioni, Annamaria Petrozza and Gianvito Vilé*,
{"title":"Tracking Charge Dynamics in a Silver Single-Atom Catalyst During the Light-Driven Oxidation of Benzyl Alcohol to Benzaldehyde","authors":"Areti Moutsiou, Andrea Olivati, Luis A. Cipriano, Alessandra Sivo, Sean M. Collins, Quentin M. Ramasse, Ik Seon Kwon, Giovanni Di Liberto, Mohamad Kanso, Robert Wojcieszak, Gianfranco Pacchioni, Annamaria Petrozza and Gianvito Vilé*, ","doi":"10.1021/acscatal.4c0520810.1021/acscatal.4c05208","DOIUrl":"https://doi.org/10.1021/acscatal.4c05208https://doi.org/10.1021/acscatal.4c05208","url":null,"abstract":"<p >Understanding charge transfer in light-driven processes is crucial for optimizing the efficiency and performance of a photocatalyst, as charge transfer directly influences the separation and migration of photogenerated charge carriers and determines the overall reaction rate and product formation. However, achieving this understanding remains challenging in the context of single-atom photocatalysis. This study addresses this gap and investigates an Ag-based single-atom catalyst (Ag<sub>1</sub>@CN<sub><i>x</i></sub>) in the photocatalytic oxidation of benzyl alcohol to benzaldehyde. Comprehensive characterization was conducted using a battery of diffractive, textural, spectroscopic, and microscopic methods, confirming the catalyst crystallinity, porosity, elemental composition, and atomic dispersion of silver atoms. This material displayed efficient performance in the selective oxidation of benzyl alcohol to benzaldehyde. Density functional theory calculations were used to rationalize the catalyst structure and elucidate the reaction mechanism, unveiling the role of the photogenerated holes in lowering the reaction energy barriers. Time-resolved transient spectroscopic studies were used to monitor the dynamics of photogenerated charges in the reaction, revealing the lifetimes and behaviors of excited states within the catalyst. Specifically, the introduction of silver atoms led to a significant enhancement in the excited state lifetime, which favors the hole-transfer in the presence of the benzyl alcohol. This indicated that the photoexcited carriers were effectively transferred to the reactant, thereby driving the oxidation process in the presence of oxygen. These mechanistic insights are pivotal in spectroscopically elucidating the reaction mechanism and can be practically applied to design single-atom photocatalysts more rationally, targeting materials that combine both rapid reductive quenching and efficient charge transfer to the metal.</p>","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"15 7","pages":"5601–5613 5601–5613"},"PeriodicalIF":11.3,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acscatal.4c05208","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143767347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ACS Catalysis Pub Date : 2025-03-21DOI: 10.1021/acscatal.4c05208
Areti Moutsiou, Andrea Olivati, Luis A. Cipriano, Alessandra Sivo, Sean M. Collins, Quentin M. Ramasse, Ik Seon Kwon, Giovanni Di Liberto, Mohamad Kanso, Robert Wojcieszak, Gianfranco Pacchioni, Annamaria Petrozza, Gianvito Vilé
{"title":"Tracking Charge Dynamics in a Silver Single-Atom Catalyst During the Light-Driven Oxidation of Benzyl Alcohol to Benzaldehyde","authors":"Areti Moutsiou, Andrea Olivati, Luis A. Cipriano, Alessandra Sivo, Sean M. Collins, Quentin M. Ramasse, Ik Seon Kwon, Giovanni Di Liberto, Mohamad Kanso, Robert Wojcieszak, Gianfranco Pacchioni, Annamaria Petrozza, Gianvito Vilé","doi":"10.1021/acscatal.4c05208","DOIUrl":"https://doi.org/10.1021/acscatal.4c05208","url":null,"abstract":"Understanding charge transfer in light-driven processes is crucial for optimizing the efficiency and performance of a photocatalyst, as charge transfer directly influences the separation and migration of photogenerated charge carriers and determines the overall reaction rate and product formation. However, achieving this understanding remains challenging in the context of single-atom photocatalysis. This study addresses this gap and investigates an Ag-based single-atom catalyst (Ag<sub>1</sub>@CN<sub><i>x</i></sub>) in the photocatalytic oxidation of benzyl alcohol to benzaldehyde. Comprehensive characterization was conducted using a battery of diffractive, textural, spectroscopic, and microscopic methods, confirming the catalyst crystallinity, porosity, elemental composition, and atomic dispersion of silver atoms. This material displayed efficient performance in the selective oxidation of benzyl alcohol to benzaldehyde. Density functional theory calculations were used to rationalize the catalyst structure and elucidate the reaction mechanism, unveiling the role of the photogenerated holes in lowering the reaction energy barriers. Time-resolved transient spectroscopic studies were used to monitor the dynamics of photogenerated charges in the reaction, revealing the lifetimes and behaviors of excited states within the catalyst. Specifically, the introduction of silver atoms led to a significant enhancement in the excited state lifetime, which favors the hole-transfer in the presence of the benzyl alcohol. This indicated that the photoexcited carriers were effectively transferred to the reactant, thereby driving the oxidation process in the presence of oxygen. These mechanistic insights are pivotal in spectroscopically elucidating the reaction mechanism and can be practically applied to design single-atom photocatalysts more rationally, targeting materials that combine both rapid reductive quenching and efficient charge transfer to the metal.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"18 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143666769","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}
ACS Catalysis Pub Date : 2025-03-21DOI: 10.1021/acscatal.4c07064
Lu Song, Juan Carlos Navarro de Miguel, Sarah Komaty, Sang-Ho Chung, Javier Ruiz-Martínez
{"title":"Role of Phosphorus on ZSM-5 Zeolite for the Methanol-to-Hydrocarbon Reaction","authors":"Lu Song, Juan Carlos Navarro de Miguel, Sarah Komaty, Sang-Ho Chung, Javier Ruiz-Martínez","doi":"10.1021/acscatal.4c07064","DOIUrl":"https://doi.org/10.1021/acscatal.4c07064","url":null,"abstract":"Phosphorus modification is a widely adopted strategy for modulating the performance of ZSM-5 catalysts in methanol-to-hydrocarbon (MTH) reactions. However, the underlying modification mechanism for the structure–performance relationship is not yet fully understood. In this study, a series of phosphorus-modified ZSM-5 (P-ZSM-5) catalysts were synthesized via direct impregnation using ammonium phosphate dibasic as the phosphorus source. With this synthetic method, the aluminum content and structural properties of zeolite are preserved. Our findings showed that phosphorus loading significantly alters the acidity and microporous properties of ZSM-5. To explore the underlying reasons for these changes, we employed <sup>31</sup>P and <sup>27</sup>Al solid-state magic angle spining (MAS) nuclear magnetic resonance (NMR), which provided chemical and structural insights. The lower amount of strong acid sites resulted in a prolonged lifetime in the MTH reaction and enhanced selectivity toward alkenes for P-ZSM-5. Additionally, the pore narrowing created by adding phosphorus had an additional effect on product selectivity by suppressing <i>o</i>-xylene yields. By using the <sup>13</sup>C, <sup>13</sup>C–<sup>13</sup>C, and <sup>1</sup>H–<sup>13</sup>C MAS NMR analysis conducted on the <sup>13</sup>C-methanol-reacted catalysts, we demonstrated direct evidence that P-ZSM-5 preserved the same MTH pathways but suppressed the formation of one of the key coke precursors, the 1,2,3-trimethylcyclopentenyl cation. This was further confirmed by the <i>operando</i> UV–vis results, along with the reduced accumulation rate of other coke precursors such as naphthalene and polyaromatics.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"56 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143666681","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}
ACS Catalysis Pub Date : 2025-03-21DOI: 10.1021/acscatal.5c00081
Lu-Lu Hao, Ji-Yun Hu, Jing Li, Yu-Jing Gao, Yin-Shan Meng, Tao Liu
{"title":"Manipulating the Intrinsic Magnetism of Spinel Catalyst toward Magnetic Field-Enhanced OER","authors":"Lu-Lu Hao, Ji-Yun Hu, Jing Li, Yu-Jing Gao, Yin-Shan Meng, Tao Liu","doi":"10.1021/acscatal.5c00081","DOIUrl":"https://doi.org/10.1021/acscatal.5c00081","url":null,"abstract":"Magnetic catalysts offer an approach to boost the sluggish kinetics of the spin-selective oxygen evolution reaction (OER) with the assistance of the spin-magnetic effect. However, the spin-magnetic effect, which is the correlation between the intrinsic magnetism and catalytic activity, has not been fully understood. Here, we manipulate the saturation magnetization (<i>M</i><sub>s</sub>) of NiCo<sub>2–<i>x</i></sub>Fe<sub><i>x</i></sub>O<sub>4</sub> via an iron-doping strategy and evaluate the magnetic field-assisted OER performance accordingly. The experimental results reveal a clear positive correlation between the <i>M</i><sub>s</sub> values and the magnetic field-enhanced OER activity. The ferromagnetically coupled NiCo<sub>1.6</sub>Fe<sub>0.4</sub>O<sub>4</sub> has the largest <i>M</i><sub>s</sub> of 8.6 emu g<sup>–1</sup>, and it exhibits the strongest spin-magnetic effect, with a 14.6% reduction of the overpotential and 31.5% reduction of the Tafel slope after applying a mild magnetic field. Density functional theory (DFT) calculations demonstrate that the adsorption energy of *OH at the high-spin cobalt active site highly depends on the <i>M</i><sub>s</sub> of ferromagnetic spinel catalysts. The increase of activity is mainly attributed to the optimized e<sub>g</sub> occupation of the high-spin cobalt ion and stronger spin-coupling between the cobalt active site and oxygenated intermediates. The elucidation of the relationship between intrinsic magnetism and field-assisted OER activity enlightens an approach toward the design of magnetic catalysts for OER and other spin-selective reactions.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"55 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143666699","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}
ACS Catalysis Pub Date : 2025-03-21DOI: 10.1021/acscatal.4c07545
Yi Zhang, Tiange Wei, Debo Ding, Keke Wang, Jun Di, Jo-chi Tseng, Yuanbin She, Molly Meng-Jung Li, Jiexiang Xia, Huaming Li
{"title":"Aggregation-Induced Equidistant Dual Pt Atom Pairs for Effective CO2 Photoreduction to C2H4","authors":"Yi Zhang, Tiange Wei, Debo Ding, Keke Wang, Jun Di, Jo-chi Tseng, Yuanbin She, Molly Meng-Jung Li, Jiexiang Xia, Huaming Li","doi":"10.1021/acscatal.4c07545","DOIUrl":"https://doi.org/10.1021/acscatal.4c07545","url":null,"abstract":"The photocatalytic conversion of CO<sub>2</sub> into high value-added ethylene (C<sub>2</sub>H<sub>4</sub>) is challenging due to the unsuitable active sites and the significant energy barrier associated with the C–C coupling process. Single-atom catalysts are advantageous for their high atom utilization efficiency, yet enhancing C–C coupling efficiency requires strategic engineering of the active site environment. Traditional approaches often result in the random spacing of active atom pairs, which can hinder C–C coupling facilitation. Dual-atom pairs with precise geometrical modulation and well-defined spacing can improve the generation of C2 products and enhance the mechanistic understanding. Herein, we present an equidistant dual Pt atom pair assembly on the Bi<sub>3</sub>O<sub>4</sub>Br surface via Pt-TCPP aggregation. Using this strategy, the spacing between neighboring Pt atoms in each atom pair is confined through intermolecular van der Waals forces, and such a geometrically well-defined site significantly facilitates the C–C coupling process. Consequently, the atom pair configuration achieves a C<sub>2</sub>H<sub>4</sub> yield over 8 times higher than that of the single atom structure, with an improved TOF of site enhancement of about 10 times. Our work highlights an effective strategy for fabricating well-defined dual-atom catalysts, offering a promising pathway for efficient CO<sub>2</sub> photoreduction to C<sub>2</sub>H<sub>4</sub> by precisely designing the photocatalytic environment.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"33 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143666698","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}
ACS Catalysis Pub Date : 2025-03-21DOI: 10.1021/acscatal.5c00372
Zhitong Zhou, Weixiang Guan, Xiaoli Pan, Aiqin Wang, Tao Zhang
{"title":"Synthesis of Pyrazines from Biomass-Derived Vicinal Diols Using Ammonia over Heterogeneous Pt/CeO2/Al2O3 Catalysts","authors":"Zhitong Zhou, Weixiang Guan, Xiaoli Pan, Aiqin Wang, Tao Zhang","doi":"10.1021/acscatal.5c00372","DOIUrl":"https://doi.org/10.1021/acscatal.5c00372","url":null,"abstract":"One-pot amination coupling of vicinal diols toward the synthesis of pyrazines provides an efficient and economically viable route to access N-heterocycles from biomass, yet the current methodology relies on a fragile homogeneous catalyst system, which limits the sustainability of the chemistry. In this work, we developed a highly efficient heterogeneous catalyst 0.8Pt/13CeO<sub>2</sub>/Al<sub>2</sub>O<sub>3</sub> which afforded diverse substituted pyrazines from readily available vicinal diols and ammonia with a yield up to 94% under mild reaction conditions and could be reused at least 6 times without obvious activity decay. Compared to the Pt/Al<sub>2</sub>O<sub>3</sub> catalyst, the 0.8Pt/13CeO<sub>2</sub>/Al<sub>2</sub>O<sub>3</sub> catalyst exhibited a 30-fold faster conversion rate of diols and an increased pyrazine selectivity from 48% to 79%. Characterizations revealed that doped CeO<sub>2</sub> improved the dispersion of Pt, increased the electron density on the Pt sites, optimized the acid/basic property of the catalyst, and enhanced the adsorption strength and dehydrogenation ability of diols. All these features contributed to the increased activity and selectivity.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"70 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143666700","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}
ACS Catalysis Pub Date : 2025-03-20DOI: 10.1021/acscatal.4c0778510.1021/acscatal.4c07785
Chunjin Huang, Yue Chen, Huihuang Fang, Guo Zhi, Chongqi Chen*, Yu Luo, Xingyi Lin and Lilong Jiang*,
{"title":"Copper Phyllosilicate-Derived Cu Catalyst for the Water–Gas Shift Reaction: Insight into the Role of Cu+–Cu0 and Reaction Mechanism","authors":"Chunjin Huang, Yue Chen, Huihuang Fang, Guo Zhi, Chongqi Chen*, Yu Luo, Xingyi Lin and Lilong Jiang*, ","doi":"10.1021/acscatal.4c0778510.1021/acscatal.4c07785","DOIUrl":"https://doi.org/10.1021/acscatal.4c07785https://doi.org/10.1021/acscatal.4c07785","url":null,"abstract":"<p >Cu-based catalysts have been extensively researched for hydrogen production via water–gas shift (WGS, CO+H<sub>2</sub>O↔CO<sub>2</sub>+H<sub>2</sub>) reaction. Yet, the catalyst easily suffers from performance degradation due to Cu<sup>+</sup>/Cu<sup>0</sup> transformation and particle aggregation. Herein, copper phyllosilicate with different morphologies, i.e., tubular and lamellar, was fabricated by a modified hydrothermal method for the WGS reaction. Compared with the catalyst derived from lamellar copper phyllosilicate (30Cu/SiO<sub>2</sub>-L), the one derived from the tubular phyllosilicate (30Cu/SiO<sub>2</sub>-T) demonstrates better performance due to the high Cu<sup>+</sup>/(Cu<sup>0</sup>+Cu<sup>+</sup>) ratio. <i>In situ</i> characterizations were conducted to unveil the transformation between Cu<sup>+</sup> and Cu<sup>0</sup>, which is highly correlated to the CO and H<sub>2</sub>O activation. Cu<sup>+</sup> is primarily responsible for the activation of CO, while Cu<sup>0</sup> mainly facilitates the dissociation of H<sub>2</sub>O. The results show that 30Cu/SiO<sub>2</sub>-T follows the redox mechanism, where CO reduces Cu<sup>+</sup> to Cu<sup>0</sup> and H<sub>2</sub>O oxidizes Cu<sup>0</sup> to Cu<sup>+</sup>, maintaining the reaction cycle.</p>","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"15 7","pages":"5546–5556 5546–5556"},"PeriodicalIF":11.3,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143767191","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}
ACS Catalysis Pub Date : 2025-03-20DOI: 10.1021/acscatal.4c05773
Sang-Mun Jung, Sinhyeop Kim, Jihun An, Kyu-Su Kim, Minseok Kim, Jaesub Kwon, Hyungjun Kim, Yong-Tae Kim, Sarah S. Park
{"title":"Synergistic Effects of Co–N4 and Ni–N4 Sites in 2D Conductive Metal–Organic Framework Electrocatalysts for Enhanced Oxygen Reduction Reaction Performance","authors":"Sang-Mun Jung, Sinhyeop Kim, Jihun An, Kyu-Su Kim, Minseok Kim, Jaesub Kwon, Hyungjun Kim, Yong-Tae Kim, Sarah S. Park","doi":"10.1021/acscatal.4c05773","DOIUrl":"https://doi.org/10.1021/acscatal.4c05773","url":null,"abstract":"Oxygen reduction reaction (ORR) is vital for energy storage and conversion technologies but is hindered by complex multielectron transfer mechanisms and sluggish kinetics. This study explores intrinsically conductive two-dimensional metal–organic frameworks (MOFs), specifically a series of Co<sub><i>x</i></sub>Ni<sub>3–<i>x</i></sub>(HITP)<sub>2</sub> (0 ≤ <i>x</i> ≤ 3) as a model system, enabling precise control over electronic properties and well-defined active site environments. By varying the Co to Ni ratio, we found that a 1:1 ratio enhances the ORR activity significantly. In situ X-ray absorption spectroscopy and density functional theory analyses reveal that Ni–N<sub>4</sub> improves conductivity and stability, while Co–N<sub>4</sub> provides high-selectivity active sites, offering a robust platform for understanding structure–function relationships in MOF-based and single-atom catalysts.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"17 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143666702","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}
ACS Catalysis Pub Date : 2025-03-20DOI: 10.1021/acscatal.5c0072010.1021/acscatal.5c00720
Abdullah J. Al Abdulghani, Unni Kurumbail, Son Dong, Natalie R. Altvater, Rick W. Dorn, Melissa C. Cendejas, William P. McDermott, Theodore O. Agbi, Collin M. Queen, Matias Alvear, Ashley R. Head, Aaron J. Rossini and Ive Hermans*,
{"title":"Preventing Loss of Selectivity during the Oxidative Dehydrogenation of Propane over Supported Vanadium Catalysts","authors":"Abdullah J. Al Abdulghani, Unni Kurumbail, Son Dong, Natalie R. Altvater, Rick W. Dorn, Melissa C. Cendejas, William P. McDermott, Theodore O. Agbi, Collin M. Queen, Matias Alvear, Ashley R. Head, Aaron J. Rossini and Ive Hermans*, ","doi":"10.1021/acscatal.5c0072010.1021/acscatal.5c00720","DOIUrl":"https://doi.org/10.1021/acscatal.5c00720https://doi.org/10.1021/acscatal.5c00720","url":null,"abstract":"<p >Supported vanadium materials are promising catalysts for the oxidative dehydrogenation of propane to propylene (ODHP), but a lack of mechanistic understanding limits the rational design of catalysts with improved propylene selectivity. Adding Ta to V/SiO<sub>2</sub> increases the propylene selectivity, as well as the activity, leading to superior performance compared to state-of-the-art boron-based systems. In this contribution, we utilize this surprising promotional effect of Ta to elucidate key elements of the mechanistic cycle. Through a combination of characterization techniques, computational modeling, and kinetic experiments, we show that the catalytic cycle over V/SiO<sub>2</sub> likely involves the formation of an isopropyl alcohol intermediate, the fate of which is in kinetic competition between subsequent dehydration to propylene or further oxidation. Furthermore, we show that the relatively facile propylene overoxidation observed for these materials occurs via the epoxidation of propylene by a proposed peroxovanadium intermediate, rather than the abstraction of propylene’s allylic C–H bond as previously assumed. Using these key mechanistic features, we rationalize the enhanced selectivity and activity of Ta promotion. Our mechanistic framework offers avenues for future catalyst development to improve supported vanadium materials for ODHP.</p>","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"15 7","pages":"5557–5567 5557–5567"},"PeriodicalIF":11.3,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143767251","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}
ACS Catalysis Pub Date : 2025-03-20DOI: 10.1021/acscatal.4c07703
Eui-Rim On, Kimoon Lee, Yeonsu Kwak, Chan Kim, Quan Dao, Hyuntae Sohn, Suk Woo Nam, Joohoon Kim, Yongmin Kim, Hyangsoo Jeong
{"title":"Promoter-Guided Reaction Intermediate Dynamics Enhance Perhydro-benzyltoluene Dehydrogenation","authors":"Eui-Rim On, Kimoon Lee, Yeonsu Kwak, Chan Kim, Quan Dao, Hyuntae Sohn, Suk Woo Nam, Joohoon Kim, Yongmin Kim, Hyangsoo Jeong","doi":"10.1021/acscatal.4c07703","DOIUrl":"https://doi.org/10.1021/acscatal.4c07703","url":null,"abstract":"The dehydrogenation of perhydrobenzyltoluene (H<sub>12</sub>-BT) as a liquid organic hydrogen carrier presents significant challenges in reaction kinetics and catalyst stability. The reaction pathway involves multiple intermediates and isomeric variations, creating an intricate network that influences both catalytic activity and deactivation mechanisms. While sulfur modification of Pt/θ-Al<sub>2</sub>O<sub>3</sub> catalysts enhances reaction rates and stability, the underlying mechanisms governing catalyst–intermediate interactions have remained elusive. To unravel these complex interactions, we developed a surrogate approach using single-ring model compounds (methylcyclohexane, dimethylcyclohexane, toluene, and xylene) as surrogates for two-ring intermediates. This strategy enabled systematic analysis of intermediate behavior without requiring challenging intermediate synthesis. Using in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) at 320 °C, we examined how sulfur modification transforms reaction pathways and surface chemistry. Our results reveal that successful dehydrogenation depends on controlled intermediate readsorption patterns. Sulfur modification promotes favorable readsorption via aliphatic moieties, facilitating complete dehydrogenation while minimizing aromatic species retention. In contrast, unmodified Pt/θ-Al<sub>2</sub>O<sub>3</sub> exhibits preferential readsorption of dehydrogenated aromatic species, leading to active-site blockage and carbon formation. Postreaction analyses confirm that sulfur maintains catalyst integrity by redirecting reaction pathways, demonstrating a broader strategy for controlling surface chemistry in complex dehydrogenation systems through selective adsorption modification.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"56 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143661093","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}