ACS Catalysis Pub Date : 2025-09-19DOI: 10.1021/acscatal.5c04794
Gaia Grando, , , Giuseppe Sportelli, , , Gaia Castellani, , , Giacomo Filippini, , , Maurizio Prato, , , Michele Melchionna*, , and , Paolo Fornasiero*,
{"title":"Toward Reliable and Reproducible Research in Organic Photocatalysis by Carbon Nitride","authors":"Gaia Grando, , , Giuseppe Sportelli, , , Gaia Castellani, , , Giacomo Filippini, , , Maurizio Prato, , , Michele Melchionna*, , and , Paolo Fornasiero*, ","doi":"10.1021/acscatal.5c04794","DOIUrl":"10.1021/acscatal.5c04794","url":null,"abstract":"<p >The rate of scientific publications has grown exponentially over the past few decades, but this has come at the expense of reproducibility. In this context, fields like organic photocatalysis and materials synthesis have also been affected. This Perspective aims at providing general guidelines to increase trustworthiness and favor reproducibility for those interdisciplinary researchers working on organic photocatalytic transformations catalyzed by carbon-nitride-based materials. Thus, the article focuses on the importance of accurately reporting and describing all the stages of experimental work, from the photocatalyst synthesis and characterization to the evaluation of the reaction conditions, control experiments, and─more generally─all the details that may ensure reproducibility. Additionally, we investigate and discuss the risks of falling into inadequate research practices, emphasizing that irreproducibility in science is a major problem that undermines the utility and credibility of scientific research. These aspects are crucial for the scientific community, and we emphasize the need to raise awareness and educate researchers toward best experimental practices.</p>","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"15 19","pages":"16792–16809"},"PeriodicalIF":13.1,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/pdf/10.1021/acscatal.5c04794","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145089709","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}
{"title":"Carbon Dioxide as a Hydrogen-Transport Modulator─Disrupting Surface Hydrogen Accumulation during Propane Aromatization","authors":"Luyuan Yang, , , Yitao Yang, , , Min Yang, , , Yumeng Fo, , , Xiangyang Ji, , , Kun Yang, , , Guilin Liu, , , YuHui Xia, , , Zhen Zhao, , , Jian Liu*, , and , Weiyu Song*, ","doi":"10.1021/acscatal.5c03541","DOIUrl":"10.1021/acscatal.5c03541","url":null,"abstract":"<p >Introducing CO<sub>2</sub> into propane (C<sub>3</sub>H<sub>8</sub>) aromatization presents a significant strategy for producing benzene, toluene, and xylene (BTX) while mitigating carbon emissions. This study demonstrates the dual role of CO<sub>2</sub> as a hydrogen-transport modulator and carbon contributor in the propane-coupled CO<sub>2</sub> aromatization (PCA) process. The Ga/M-Z5 catalyst, with Ga-rich outer layers for CO<sub>2</sub> activation and Al-rich channel intersections for aromatization, was achieved through alkali treatment of the support and subsequent chemical liquid deposition (CLD) of the active phase. This catalyst yielded a 54% CO<sub>2</sub> conversion and 63% BTX selectivity. The improved BTX selectivity stems from the efficient capture of hydrogen (H*) by CO<sub>2</sub>. Mechanistic investigations, including kinetic analyses, in situ Fourier transform infrared (FTIR), mass spectrometry, and density functional theory (DFT) calculations, revealed that H* spontaneously transfers from Brønsted acid sites (BAS) to Ga–O bonds. CO<sub>2</sub> facilitates the extraction of H* through a pentagonal Ga–O intermediate, thereby suppressing hydrogen-induced side reactions. The high CO<sub>2</sub> conversion indicates that CO<sub>2</sub> participates in additional pathways beyond reverse water gas shift (RWGS) and reverse Boudouard reactions. Specifically, partial CO<sub>2</sub> interacts with oxygen-containing intermediate species, directly contributing to the reconstruction of carbon chains and the formation of aromatic products. These findings provide insights for optimizing catalyst design in PCA systems.</p>","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"15 19","pages":"16771–16781"},"PeriodicalIF":13.1,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145084108","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}
{"title":"Mechanistic Insights into Synergistic Enhancement of Linear α-Olefins Selectivity over Ca–Na Modified Fe5C2–ZnO Catalysts in CO Hydrogenation","authors":"Hengxuan Zhang, , , Yan Sun*, , , Qiwen Sun*, , , Jiancheng Wang, , , Zixing Shi, , and , Junjie Liu, ","doi":"10.1021/acscatal.5c04615","DOIUrl":"10.1021/acscatal.5c04615","url":null,"abstract":"<p >Selective synthesis of long-chain linear α-olefins (LAOs) from syngas remains a fundamental challenge due to competitive hydrogenation and water–gas shift (WGS) reactions. Herein, we report that CaO- and Na<sub>2</sub>O-promoted Fe<sub>5</sub>C<sub>2</sub>–ZnO catalyst (FeZnCaNa) demonstrates prominent performance and stability in CO hydrogenation to LAOs, which achieved 97.4% of CO conversion, 73.7% of LAOs in C<sub>4+</sub> olefins with LAOs space-time yield of 304.4 mg·g<sub>cat</sub><sup>–1</sup>·h<sup>–1</sup> at 320 °C, 2.0 MPa. Comparative studies of modification with other alkaline earth metals (Mg, Sr, and Ba) underscored the unique promotional role of Ca in enhancing LAOs yield. The characterizations revealed that CaO accelerated the transformation of ZnFe<sub>2</sub>O<sub>4</sub> into dispersed χ-Fe<sub>5</sub>C<sub>2</sub> domains anchored at the ZnO interface. These iron carbide domains served as the principal active sites for the CO dissociation and C–C coupling. The Ca–Na–ZnO matrix modulated surface basicity, facilitating olefin desorption, and suppressing secondary hydrogenation. The ratio of olefin/paraffin attained 4.5, 58.6% of α-olefins in hydrocarbons, and suppressed CH<sub>4</sub> selectivity to 8.1%. In situ spectroscopic analyses further explained that CaO–Na<sub>2</sub>O incorporation promoted CH<sub><i>x</i></sub> formation, thereby accelerating chain propagation. The catalyst also exhibited a reduced CO<sub>2</sub> selectivity of 30.5%, attributed to the attenuated WGS activity resulting from decreased H<sub>2</sub>O adsorption during hydrocarbon formation. This study uncovers a dual-site mechanism, offering insights for designing efficient Fe-based catalysts for viable syngas-to-olefins conversion.</p>","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"15 19","pages":"16810–16826"},"PeriodicalIF":13.1,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145084110","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}
{"title":"Regio- and Diastereoselective Construction of Multisubstituted C-Vinyl Glycosides via Nickel-Catalyzed Three-Component Reaction of Alkynes","authors":"Jinlin Wang, , , Changyue Yu, , , Qiuyu Zhong, , , Mingjie Zeng, , , Xiaofei He, , , Chunpu Li, , , Jiang Wang, , , Wenhao Dai*, , and , Hong Liu*, ","doi":"10.1021/acscatal.5c03229","DOIUrl":"10.1021/acscatal.5c03229","url":null,"abstract":"<p ><i>C</i>-vinyl glycosides are important carbohydrates with various biological activities and promising applications. However, the efficient synthesis of <i>C</i>-vinyl glycosides remains challenging, typically relying on two-component couplings of glycosyl donors with olefins or alkynes. These methods often involve air-sensitive organometallic reagents, directing groups, or activating group preactivation. Notably, the construction of multisubstituted <i>C</i>-vinyl glycosides directly from alkynes remains largely underexplored in synthetic carbohydrate chemistry. Here, a convenient and efficient method for the regio- and diastereoselective synthesis of multisubstituted <i>C</i>-vinyl glycosides via a nickel-catalyzed three-component reaction involving terminal alkynes, boronic acids, and glycosyl bromides in one pot is presented. This reaction proceeds by a radical pathway and demonstrates excellent regio- and diastereoselectivity, as evidenced by the α-selective, <i>trans</i>-addition products and the addition of the glycosyl moiety installed at the terminal position of the alkyne. This method utilizes commercially available starting materials without the need for additional preactivation, features a straightforward operational procedure, and demonstrates a broad substrate scope and functional group tolerance. Furthermore, this method is suitable for the late-stage glycosylation modification of complex natural products. Overall, this approach provides a widely applicable method to synthesize multisubstituted <i>C</i>-vinyl glycosides using simple and readily available three-component starting materials in one pot.</p>","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"15 19","pages":"16762–16770"},"PeriodicalIF":13.1,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145084107","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}
{"title":"Aqueous Synthesis of Bio-Based 3-Hydroxyl Propionic Acid: Unique Substrate/Product Inhibition Effect over PtAu/TiO2 and Pt/TiO2 Catalysts","authors":"Wenhan Li, , , Fan Li, , , Yuangao Wang, , , Xin Wang, , , Dongpei Zhang, , , Wei Yu, , , Mengyuan Liu*, , , Xin Jin*, , and , Chaohe Yang, ","doi":"10.1021/acscatal.5c03165","DOIUrl":"10.1021/acscatal.5c03165","url":null,"abstract":"<p >3-Hydroxypropionic acid (HPA) is an important platform molecule in the polyester industry. However, the synthesis of biobased HPA has been largely unexplored in this field. We reported the aqueous oxidation of bioderived 1,3-propanediol (1,3-PDO) to HPA over bimetallic PtAu/TiO<sub>2</sub> catalysts, achieving a yield of 84.5% and a notably high turnover frequency (TOF) value of 871 h<sup>–1</sup> at 80 °C and 1 MPa O<sub>2</sub> in alkali-free medium. One of the key findings is that <i>d</i>-band upshifted PtAu/TiO<sub>2</sub> catalysts exhibit enhanced catalytic activity due to strong −OH/Pt coordination under a low concentration of 1,3-PDO (<0.3 M). However, under high 1,3-PDO concentration (>1.0 M), these catalysts show pronounced inhibition and poor activity. In sharp contrast, a monometallic Pt/TiO<sub>2</sub> catalyst with poor −OH/Pt coordination but strong −COOH/Pt coupling exhibits an unusual product inhibition by HPA according to experimental studies. Computational investigation has further revealed that the tunable shift of the <i>d</i>-band center in bimetallic PtAu clusters is the critical descriptive factor determining the coordination of −OH and −COOH with Pt sites. The mechanistic insights provide both experimental and theoretical foundation for designing industrial catalysts for polyol oxidation toward value-added commodity chemicals.</p>","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"15 19","pages":"16703–16717"},"PeriodicalIF":13.1,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145084111","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 : 2025-09-18DOI: 10.1021/acscatal.5c06069
Ritu, , , Matthias Schmitz, , , Chris Burdenski, , , Patrick W. Antoni, , , Julian J. Holstein, , , Christoph Kerzig*, , and , Max M. Hansmann*,
{"title":"π-Extended Heterocycle/Carbene Hybrids as Geometrically Constrained Dyes for TADF Energy and Electron Transfer Photocatalysis","authors":"Ritu, , , Matthias Schmitz, , , Chris Burdenski, , , Patrick W. Antoni, , , Julian J. Holstein, , , Christoph Kerzig*, , and , Max M. Hansmann*, ","doi":"10.1021/acscatal.5c06069","DOIUrl":"10.1021/acscatal.5c06069","url":null,"abstract":"<p >We present an organic redox system derived from the combination of <i>N</i>-heterocyclic carbenes with azadibenzo[<i>e</i>,<i>l</i>]pyrene. It features three stable oxidation states, which could be isolated and structurally characterized and are supported by nuclear magnetic resonance (NMR), electron paramagnetic resonance (EPR) spectroscopy, and X-ray analysis. Due to the rigid π-extended heterocyclic framework, geometrical changes during the redox cycling are reduced to a minimum, resulting exclusively in the rotation of the central C–C bond and a potential expansion in the cyclic voltammogram. The photoactive chromophore, which shows thermally activated delayed fluorescence (TADF) behavior, was employed in the dicationic oxidation state as a photosensitizer for C–N-coupling via the direct oxidation of benzene and biphenyl derivatives, intramolecular [2 + 2] cycloadditions of olefins, and isomerization of activated olefins mediated by energy transfer, which represents a promising alternative to metal-based systems. The versatile photocatalyst has a similar triplet state energy (∼2.3 eV) and a much longer triplet state lifetime (64 μs) compared to well-established metal-based sensitizers. Mechanistic experiments using time-resolved emission and transient absorption spectroscopy demonstrate the highly oxidizing excited state, the remarkable lifetime of the high-energy triplet state, and they support key mechanistic steps and intermediates.</p>","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"15 19","pages":"16718–16730"},"PeriodicalIF":13.1,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145084112","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}
{"title":"Gold-Catalyzed Intermolecular 1,2-Difunctionalization of Alkynes with Aryl Iodides","authors":"Lizhu Zhang, , , Gang Li, , , Jiawen Wu, , , Rongjie Yang, , , Shuang Luo*, , and , Zhonghua Xia*, ","doi":"10.1021/acscatal.5c03719","DOIUrl":"10.1021/acscatal.5c03719","url":null,"abstract":"<p >Compared with traditional transition metals, gold-catalyzed 1,2-difunctionalization of C–C multiple bonds has introduced a new paradigm. Herein, we report an unexplored gold-catalyzed intermolecular 1,2-difunctionalization of alkynes with aryl iodides in an EtOH/H<sub>2</sub>O mixture, furnishing a variety of α-aryl ketones, overcoming challenges such as facile hydrofunctionalization and direct cross-coupling. Under the influence of the hemilabile MeDalphos ligand gold catalyst, various alkynes underwent 1,2-difunctionalization with different aryl iodides, achieving a high efficiency and good regioselectivity to form α-aryl ketones in a one-pot reaction. This approach eliminates the need for strong external oxidants and the photocatalytic activation of aryl diazonium salts. Mechanistic and theoretical studies support a reaction pathway that effectively integrates the oxidative addition of aryl iodides and the π-activation of alkynes in gold(I)/gold(III) catalysis.</p>","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"15 19","pages":"16731–16739"},"PeriodicalIF":13.1,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145083950","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 : 2025-09-17DOI: 10.1021/acscatal.5c04795
Simone Perego, , , Maximilian Purcel, , , Yannick Baum, , , Shilong Chen*, , , Astrid Sophie Müller, , , Michele Parrinello, , , Malte Behrens, , , Martin Muhler, , and , Luigi Bonati*,
{"title":"No Time for Nitrides: How Cobalt Alloying Promotes Iron Catalysts for Ammonia Decomposition","authors":"Simone Perego, , , Maximilian Purcel, , , Yannick Baum, , , Shilong Chen*, , , Astrid Sophie Müller, , , Michele Parrinello, , , Malte Behrens, , , Martin Muhler, , and , Luigi Bonati*, ","doi":"10.1021/acscatal.5c04795","DOIUrl":"10.1021/acscatal.5c04795","url":null,"abstract":"<p >The increasing demand for hydrogen production has driven interest in ammonia decomposition. Iron-based catalysts, widely used for ammonia synthesis, exhibit suboptimal performance in the reverse process due to their tendency to form iron nitrides. Recent experiments have shown that alloying iron with cobalt enhances the catalytic activity (Chen et al., <i>Nat. Commun.</i> 15, 871, 2024), yet the microscopic origin of this promotional effect is not fully understood. To address this, we leverage recent developments in machine learning-based molecular dynamics simulations to investigate the key reactions of the catalytic cycle, fully accounting for dynamical lateral interactions on the catalyst surface. Our simulations reveal that cobalt alloying provides a dual promotional effect: it slightly lowers the free energy barrier for nitrogen recombination, which is the rate-determining step for ammonia decomposition on iron, while significantly suppressing nitrogen migration into the bulk, thereby preventing nitride formation. These insights are supported by complementary transient decomposition experiments and desorption measurements, which confirm the enhanced activity and resistance to nitridation in FeCo alloys compared to monometallic iron catalysts. Furthermore, long-term stability tests demonstrate that the FeCo catalyst sustains high ammonia conversion over extended time scales. By capturing the complex interplay of competing dynamical processes at the atomic scale, our results highlight the importance of going beyond static structure–property relationships to gain mechanistic insights that can guide the rational design of more robust and efficient catalysts.</p>","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"15 19","pages":"16690–16702"},"PeriodicalIF":13.1,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/pdf/10.1021/acscatal.5c04795","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145073082","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 : 2025-09-17DOI: 10.1021/acscatal.5c05406
Wei Li*, , , Tao Guo, , , Zaitian He, , , Jingdai Wang, , and , Yongrong Yang,
{"title":"Stepwise Detitanation of Ziegler–Natta Catalysts: Unraveling the Role of Dormant Active Species in Ethylene Polymerization","authors":"Wei Li*, , , Tao Guo, , , Zaitian He, , , Jingdai Wang, , and , Yongrong Yang, ","doi":"10.1021/acscatal.5c05406","DOIUrl":"10.1021/acscatal.5c05406","url":null,"abstract":"<p >Investigating the correlation between the active center structure and chain structures of the synthesized polyethylene in Ziegler–Natta catalysts has remained a persistent challenge due to the diversity and complexity of their active sites, limiting the development of advanced catalysts for the synthesis of high-performance polyethylene. Here, we present a strategy for the stepwise removal of active species in classical ZN catalysts. The reaction product formed between disilanolisobutyl polyhedral oligomeric silsesquioxane (2OH-POSS) and TiCl<sub>4</sub> is successfully separated from the original catalyst by exploiting the solubility of 2OH-POSS in <i>n</i>-hexane, achieving a significant reduction in titanium content from 10.2 wt % to just 0.77 wt %. Advanced spectroscopic characterizations (e.g., EPR, CO-FTIR, and UV–vis) reveal a synergistic interplay between MgCl<sub>2</sub> lattice reorganization and titanium removal during this detitanation process. As detitanation progresses, residual active Ti species on the MgCl<sub>2</sub> surfaces facilitate the formation of isolated Ti<sup>3+</sup> sites. More significantly, this process dramatically enhances the formation of dormant active species, achieving the maximum content of 24.56 wt %. The catalysts enriched with dormant active species enhance the uniformity of the short-chain branching distribution in synthesized ethylene/1-hexene copolymers. Notably, upon hydrogen introduction during ethylene polymerization, these dormant-species-enriched catalysts simultaneously reduce the polyethylene molecular weight while unexpectedly enhancing the activity by 52.9%, representing the first report of such coupled effects in the ethylene polymerization of Ziegler–Natta catalysts.</p>","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"15 19","pages":"16664–16673"},"PeriodicalIF":13.1,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145072096","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 : 2025-09-17DOI: 10.1021/acscatal.5c02817
Kayla Eudy, , , Shyam Deo, , , Zayne M. Weber, , , Michael J. Janik*, , and , Robert M. Rioux*,
{"title":"Dynamic Variation of Ni and Pt Single Atom Oxidation States on CeO2 Nanocubes during CO Oxidation","authors":"Kayla Eudy, , , Shyam Deo, , , Zayne M. Weber, , , Michael J. Janik*, , and , Robert M. Rioux*, ","doi":"10.1021/acscatal.5c02817","DOIUrl":"10.1021/acscatal.5c02817","url":null,"abstract":"<p >Palladium single atoms supported on ceria nanocubes demonstrate unique catalytic behavior during CO oxidation, allowing the metal atom to access two redox cycles and oscillate between four oxidation states. Ni and Pt single atoms supported on ceria nanocubes are active for CO oxidation but do not exhibit the same unique behavior as Pd/CeO<sub>2</sub> single-atom catalysts (SACs). Experimentally measured CO reaction orders for Ni/CeO<sub>2</sub> and Pt/CeO<sub>2</sub> SACs are less than one, indicating the catalytic cycle accesses only three oxidation states. IR spectroscopy reveals a narrow range of Ni (Ni<sup>2+</sup> and Ni<sup>4+</sup>) and Pt (Pt<sup>2+</sup>) oxidation states under lean and rich CO conditions. Density functional theory calculations demonstrate oxygen vacancies cannot form adjacent to adsorbed Ni atoms, and the formation of PtO<sub>2</sub> is kinetically infeasible, limiting these SACs to a simpler redox cycle relative to Pd single atoms. Microkinetic modeling, utilizing Bayesian inference to allow the elementary energetics to vary, successfully matches experimental reaction orders and apparent barriers for Ni/CeO<sub>2</sub> and Pt/CeO<sub>2</sub> SACs with a mechanism using a single redox cycle. The kinetic behavior of single metal atoms supported on ceria nanocubes highlights how different metals have mechanistic differences during CO oxidation. The delineation of the oxidation states accessible to each metal atom may also guide their use in other catalytic chemistries.</p>","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"15 19","pages":"16674–16689"},"PeriodicalIF":13.1,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145073088","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}