A strategy for synthesizing bimetallic catalysts confined within zeolite frameworks, offering a promising approach for stabilizing metal species under harsh reaction conditions, is disclosed. A dual-stage synthesis strategy including alkali etching to open the channels of Silicalite-1 (S-1) zeolite, exposing internal hydroxyl defects that serve as anchoring sites for Cu and Zn species, is presented. This was followed by a dry-gel conversion encapsulation step to yield Cu-ZnO@S-1 catalyst. The competitive occupation of these sites by Cu and Zn facilitates the formation of high-density Cu-ZnO interfaces. Under reaction conditions of 3 MPa and 250 °C, the catalyst achieves a methanol selectivity above 99.2% and a space-time yield (STY) of 2.1 g gCu–1 h–1, nearly four times higher than that of copper-containing catalyst (Cu@S-1, 0.54 g gCu–1 h–1) and significantly outperforming the sample prepared by conventional impregnation (Cu-ZnO/S-1, 1.6 g gCu–1 h–1). The oxygen-deficient Cu-ZnO1–x sites at the Cu-ZnO interface are further demonstrated to serve as genuine active centers for methanol synthesis. The methanol formation reaction proceeds via the formate pathway, and the high density of Cu-ZnO1–x sites effectively lowers the activation barrier for the hydrogenation of *HCOO to *H2COO.
公开了一种合成限制在沸石框架内的双金属催化剂的策略,为在恶劣反应条件下稳定金属物种提供了一种有前途的方法。提出了一种双阶段合成策略,包括碱蚀刻打开硅石-1 (S-1)沸石的通道,暴露内部羟基缺陷,作为Cu和Zn的锚定位点。接下来是干凝胶转化包封步骤,得到Cu-ZnO@S-1催化剂。Cu和Zn对这些位置的竞争占据有利于高密度Cu- zno界面的形成。在3 MPa和250℃的反应条件下,催化剂的甲醇选择性达到99.2%以上,空时产率达到2.1 g gCu-1 h-1,比含铜催化剂(Cu@S-1, 0.54 g gCu-1 h-1)高出近4倍,显著优于常规浸渍法制备的样品(Cu-ZnO/S-1, 1.6 g gCu-1 h-1)。Cu-ZnO界面上的缺氧Cu-ZnO1-x位点被进一步证明是甲醇合成的真正活性中心。甲醇生成反应通过甲酸途径进行,Cu-ZnO1-x位点的高密度有效降低了*HCOO加氢成*H2COO的激活势垒。
{"title":"Engineering Cu-ZnO in Hydroxyl-Rich Zeolite for High-Performance CO2-to-Methanol Conversion","authors":"Xianglong Meng, Yanjiao Wang, Ruiping Deng, Soryong Chae, Chunzheng Wang, Girolamo Giordano, Zifeng Yan, Hailing Guo, Svetlana Mintova","doi":"10.1021/acscatal.5c08792","DOIUrl":"https://doi.org/10.1021/acscatal.5c08792","url":null,"abstract":"A strategy for synthesizing bimetallic catalysts confined within zeolite frameworks, offering a promising approach for stabilizing metal species under harsh reaction conditions, is disclosed. A dual-stage synthesis strategy including alkali etching to open the channels of Silicalite-1 (S-1) zeolite, exposing internal hydroxyl defects that serve as anchoring sites for Cu and Zn species, is presented. This was followed by a dry-gel conversion encapsulation step to yield Cu-ZnO@S-1 catalyst. The competitive occupation of these sites by Cu and Zn facilitates the formation of high-density Cu-ZnO interfaces. Under reaction conditions of 3 MPa and 250 °C, the catalyst achieves a methanol selectivity above 99.2% and a space-time yield (STY) of 2.1 g g<sub>Cu</sub><sup>–1</sup> h<sup>–1</sup>, nearly four times higher than that of copper-containing catalyst (Cu@S-1, 0.54 g g<sub>Cu</sub><sup>–1</sup> h<sup>–1</sup>) and significantly outperforming the sample prepared by conventional impregnation (Cu-ZnO/S-1, 1.6 g g<sub>Cu</sub><sup>–1</sup> h<sup>–1</sup>). The oxygen-deficient Cu-ZnO<sub>1–<i>x</i></sub> sites at the Cu-ZnO interface are further demonstrated to serve as genuine active centers for methanol synthesis. The methanol formation reaction proceeds via the formate pathway, and the high density of Cu-ZnO<sub>1–<i>x</i></sub> sites effectively lowers the activation barrier for the hydrogenation of *HCOO to *H<sub>2</sub>COO.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"17 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2026-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146129506","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}
Cobalt-based phosphides, sulfides, and selenides (Co-Xides, X = P, S, Se) are promising corrosion-resistant anode catalysts for seawater electrolysis, which stems from the reconstruction of oxyanion layers (PO43–, SO42–, SeO42–) that electrostatically repel Cl– adsorption. However, in the restructured CoOOH species, the OH species is overstabilized by a rigid dual-site bridging configuration (Co–OH–Co), which significantly increases the energy barrier for the subsequent OER steps. To overcome the limitation of high barrier for the rate-determining step of OER, d10-configured elements M (M = In, Sb, Sn) are introduced to construct an asymmetric d–p–p configuration Co–OH–M (d10) that breaks the excessive stabilization of OH and weakens OH adsorption by leveraging the mismatch in orbital energy and symmetry. In situ characterization and density functional theory calculations confirmed that the asymmetric Co–OH–M (d10) adsorption configuration reduced the surface OH coverage, thereby significantly enhancing the oxygen evolution reaction (OER) activity for seawater electrolysis. Notably, the representative Sn–CoOOH–PO43– catalyst demonstrates satisfactory catalytic performance and durability, achieving a long-term stability of 1000 h at 750 mA cm–2 (1.78 V) in simulated seawater electrolysis and 500 h at 500 mA cm–2 (2.05 V) in alkaline natural seawater electrolysis.
钴基磷化物、硫化物和硒化物(Co-Xides, X = P, S, Se)是海水电解中很有前途的耐腐蚀阳极催化剂,这源于氧阴离子层(PO43 -, SO42 -, SeO42 -)的重建,这些氧化阴离子层可以静电排斥Cl -吸附。然而,在重组的CoOOH中,OH被刚性双位点桥接结构(Co-OH-Co)过度稳定,这显著增加了后续OER步骤的能量势垒。为了克服OER决定速率步骤的高势垒限制,引入d10构型元素M (M = In, Sb, Sn)构建了不对称的d-p-p构型Co-OH-M (d10),利用轨道能量和对称性的不匹配打破了OH的过度稳定,减弱了OH的吸附。原位表征和密度泛函理论计算证实,不对称Co-OH-M (d10)吸附构型降低了表面OH覆盖,从而显著提高了海水电解的析氧反应(OER)活性。值得注意的是,具有代表性的Sn-CoOOH-PO43 -催化剂表现出了令人满意的催化性能和耐久性,在模拟海水电解中,在750 mA cm-2 (1.78 V)下实现了1000 h的长期稳定性,在碱性自然海水电解中,在500 mA cm-2 (2.05 V)下实现了500 h的长期稳定性。
{"title":"Alleviating OH Blockage: Asymmetric Adsorption Configuration of Co–OH–M (d10) for Seawater Electrolysis","authors":"Shen Wang, Jiachen Zhang, Shuyu Jia, Qicheng Liu, Jialin Li, Jiali Wang, Yawen Tang, Hanjun Sun","doi":"10.1021/acscatal.5c08465","DOIUrl":"https://doi.org/10.1021/acscatal.5c08465","url":null,"abstract":"Cobalt-based phosphides, sulfides, and selenides (Co-Xides, X = P, S, Se) are promising corrosion-resistant anode catalysts for seawater electrolysis, which stems from the reconstruction of oxyanion layers (PO<sub>4</sub><sup>3–</sup>, SO<sub>4</sub><sup>2–</sup>, SeO<sub>4</sub><sup>2–</sup>) that electrostatically repel Cl<sup>–</sup> adsorption. However, in the restructured CoOOH species, the OH species is overstabilized by a rigid dual-site bridging configuration (Co–OH–Co), which significantly increases the energy barrier for the subsequent OER steps. To overcome the limitation of high barrier for the rate-determining step of OER, d<sup>10</sup>-configured elements M (M = In, Sb, Sn) are introduced to construct an asymmetric d–p–p configuration Co–OH–M (d<sup>10</sup>) that breaks the excessive stabilization of OH and weakens OH adsorption by leveraging the mismatch in orbital energy and symmetry. In situ characterization and density functional theory calculations confirmed that the asymmetric Co–OH–M (d<sup>10</sup>) adsorption configuration reduced the surface OH coverage, thereby significantly enhancing the oxygen evolution reaction (OER) activity for seawater electrolysis. Notably, the representative Sn–CoOOH–PO<sub>4</sub><sup>3–</sup> catalyst demonstrates satisfactory catalytic performance and durability, achieving a long-term stability of 1000 h at 750 mA cm<sup>–2</sup> (1.78 V) in simulated seawater electrolysis and 500 h at 500 mA cm<sup>–2</sup> (2.05 V) in alkaline natural seawater electrolysis.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"41 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2026-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146129665","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}
Single-atom catalysts (SACs) demonstrate immense potential in energy conversion and environmental remediation due to their extreme atomic utilization and well-defined active sites. However, transitioning SACs from laboratory research to industrial applications remains challenging because scalable and controllable synthesis must be achieved while ensuring stability and seamless integration into functional devices. This review systematically summarizes recent advances in large-scale synthesis strategies for SACs, with a focus on the scientific principles governing precursor design, coordination environment modulation, and support interactions in determining the final atomic dispersion, metal loading, and stability across various synthesis routes, such as pyrolysis, molten salt templating, and ball-milling. Furthermore, the advantages of emerging techniques, such as Joule heating, microwave, and low-temperature synthesis, in the precise construction of active sites are thoroughly examined. Importantly, this review prospectively outlines design pathways for industrial applications, scalable synthesis routes utilizing waste materials, and integration strategies of SACs into catalytic membranes and electrochemical devices. These approaches effectively address key bottlenecks, including mass transfer limitations, catalyst recovery, and process scale-up. This review aims to provide a framework and theoretical guidance for the structure–function relationship from atomic structure to macroscopic performance, facilitating the transition of SACs from laboratory applications to industrial applications.
{"title":"Single-Atom Catalysts at the Crossroads: Navigating the Path from Laboratory Synthesis to Real-World Devices","authors":"Haojie Chen, Zhuo Huang, Jiajie Wang, Yuqi Zhu, Xinyu Liu, Gaoxia Zhang, Qianhui Li, Huihui Dai, Suhua Chen, Hongda Liu, Ziwei Wang, Jianping Zou","doi":"10.1021/acscatal.5c08694","DOIUrl":"https://doi.org/10.1021/acscatal.5c08694","url":null,"abstract":"Single-atom catalysts (SACs) demonstrate immense potential in energy conversion and environmental remediation due to their extreme atomic utilization and well-defined active sites. However, transitioning SACs from laboratory research to industrial applications remains challenging because scalable and controllable synthesis must be achieved while ensuring stability and seamless integration into functional devices. This review systematically summarizes recent advances in large-scale synthesis strategies for SACs, with a focus on the scientific principles governing precursor design, coordination environment modulation, and support interactions in determining the final atomic dispersion, metal loading, and stability across various synthesis routes, such as pyrolysis, molten salt templating, and ball-milling. Furthermore, the advantages of emerging techniques, such as Joule heating, microwave, and low-temperature synthesis, in the precise construction of active sites are thoroughly examined. Importantly, this review prospectively outlines design pathways for industrial applications, scalable synthesis routes utilizing waste materials, and integration strategies of SACs into catalytic membranes and electrochemical devices. These approaches effectively address key bottlenecks, including mass transfer limitations, catalyst recovery, and process scale-up. This review aims to provide a framework and theoretical guidance for the structure–function relationship from atomic structure to macroscopic performance, facilitating the transition of SACs from laboratory applications to industrial applications.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"182 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2026-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146129504","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 : 2026-02-07DOI: 10.1021/acscatal.5c08406
Lichao Lin, Chunming Ye, Linqi Shen, Xiumei Li, Zizhong Zhang, Yongfan Zhang, Tao Ji, Wenyue Su
Photocatalytic CO2-to-CO conversion enables carbon recycling, but poor selectivity remains a challenge due to complex electron and proton transfers. Ag3PO4/LaTiO2N composites are synthesized via in situ chemical precipitation and achieve a CO yield of 8.94 μmol·g–1 after 3 h under simulated solar light with 97.6% selectivity. UV–vis DRS, in situ XPS, TRPL, and EPR reveal that Ag3PO4 loading expands visible-light harvesting, forms an S-scheme heterojunction that extends the carrier lifetime (0.58 → 0.75 ns), and reduces surface oxygen-vacancy (OV) density. In situ DRIFTS and DFT calculations reveal that low OV surfaces stabilize a tridentate carbonate configuration (O–C–O 128.61°), enabling nearly spontaneous *CO desorption (ΔG = −0.03 eV) while disfavoring *CHO formation (+0.73 eV). In contrast, high OV surfaces favor a bidentate configuration (O–C–O = 123.57°) that promotes *CO hydrogenation and CH4 formation. By tuning of surface OVs, Ag3PO4/LaTiO2N selectively produces CO as the sole product. This work demonstrates that surface-vacancy engineering is a key strategy for controlling CO2 reduction selectivity and provides an approach for designing efficient, selective CO2-to-CO photocatalysts.
{"title":"Reducing Surface oxygen Vacancies in LaTiO2N Enhances CO Selectivity by Tuning CO2 Adsorption","authors":"Lichao Lin, Chunming Ye, Linqi Shen, Xiumei Li, Zizhong Zhang, Yongfan Zhang, Tao Ji, Wenyue Su","doi":"10.1021/acscatal.5c08406","DOIUrl":"https://doi.org/10.1021/acscatal.5c08406","url":null,"abstract":"Photocatalytic CO<sub>2</sub>-to-CO conversion enables carbon recycling, but poor selectivity remains a challenge due to complex electron and proton transfers. Ag<sub>3</sub>PO<sub>4</sub>/LaTiO<sub>2</sub>N composites are synthesized via in situ chemical precipitation and achieve a CO yield of 8.94 μmol·g<sup>–1</sup> after 3 h under simulated solar light with 97.6% selectivity. UV–vis DRS, in situ XPS, TRPL, and EPR reveal that Ag<sub>3</sub>PO<sub>4</sub> loading expands visible-light harvesting, forms an S-scheme heterojunction that extends the carrier lifetime (0.58 → 0.75 ns), and reduces surface oxygen-vacancy (OV) density. In situ DRIFTS and DFT calculations reveal that low OV surfaces stabilize a tridentate carbonate configuration (O–C–O 128.61°), enabling nearly spontaneous *CO desorption (Δ<i>G</i> = −0.03 eV) while disfavoring *CHO formation (+0.73 eV). In contrast, high OV surfaces favor a bidentate configuration (O–C–O = 123.57°) that promotes *CO hydrogenation and CH<sub>4</sub> formation. By tuning of surface OVs, Ag<sub>3</sub>PO<sub>4</sub>/LaTiO<sub>2</sub>N selectively produces CO as the sole product. This work demonstrates that surface-vacancy engineering is a key strategy for controlling CO<sub>2</sub> reduction selectivity and provides an approach for designing efficient, selective CO<sub>2</sub>-to-CO photocatalysts.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"48 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2026-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146129673","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 : 2026-02-07DOI: 10.1021/acscatal.5c09130
Vaibhav Bhatt, Kshatresh Dutta Dubey
In this study, we reveal a long-standing mechanistic conundrum of the functions of two very similar isozymes, CYP1A1 and CYP1A2, that possess nearly identical active-site architectures yet display a perplexing difference in their reactivities toward the flavonoid α-naphthoflavone (ANF). CYP1A1 efficiently catalyzes epoxidation, whereas CYP1A2 shows negligible activity. This contrast is especially striking because the crystallographic orientation of ANF is the same in both enzymes, and the reactive carbon lies far from the heme-oxo center. To resolve this long-standing puzzle, we combined extensive molecular dynamics simulations with hybrid QM/MM calculations. Our results reveal that the divergent reactivity arises not from differences in substrate binding, but from distinct water architecture within the catalytic pocket. CYP1A1 forms an open, well-organized aqueduct connecting the heme to the reactive carbon center, facilitating epoxidation, whereas CYP1A2 lacks such an organized channel. This contrast is attributed to the different synchronized movements of the F and I helices, resulting in altered side-chain packing between key residues controlling the solvent gate. Site-directed mutations confirm the reopening of the closed water gate in CYP1A2 and re-establish water occupancy. Hybrid QM/MM calculations further reveal that ANF epoxidation proceeds through a sequential water-mediated relay culminating in an asynchronous proton-coupled electron transfer (PCET) step that yields the experimentally observed 5,6 oxide. These findings establish that subtle second-shell variations reshape water topology and thereby control catalytic competence in two deceptively similar P450 isozymes, providing a unified mechanistic explanation for their divergent reactivity.
{"title":"Different Water Architecture Diversifies the Catalytic Activity in Two Deceptively Similar Cytochrome P450 Isozymes","authors":"Vaibhav Bhatt, Kshatresh Dutta Dubey","doi":"10.1021/acscatal.5c09130","DOIUrl":"https://doi.org/10.1021/acscatal.5c09130","url":null,"abstract":"In this study, we reveal a long-standing mechanistic conundrum of the functions of two very similar isozymes, CYP1A1 and CYP1A2, that possess nearly identical active-site architectures yet display a perplexing difference in their reactivities toward the flavonoid α-naphthoflavone (ANF). CYP1A1 efficiently catalyzes epoxidation, whereas CYP1A2 shows negligible activity. This contrast is especially striking because the crystallographic orientation of ANF is the same in both enzymes, and the reactive carbon lies far from the heme-oxo center. To resolve this long-standing puzzle, we combined extensive molecular dynamics simulations with hybrid QM/MM calculations. Our results reveal that the <i>divergent reactivity arises not from differences in substrate binding</i>, but from distinct water architecture within the catalytic pocket. CYP1A1 forms an open, well-organized aqueduct connecting the heme to the reactive carbon center, facilitating epoxidation, whereas CYP1A2 lacks such an organized channel. This contrast is attributed to the different synchronized movements of the F and I helices, resulting in altered side-chain packing between key residues controlling the solvent gate. Site-directed mutations confirm the reopening of the closed water gate in CYP1A2 and re-establish water occupancy. Hybrid QM/MM calculations further reveal that ANF epoxidation proceeds through a sequential water-mediated relay culminating in an asynchronous proton-coupled electron transfer (PCET) step that yields the experimentally observed 5,6 oxide. These findings establish that subtle second-shell variations reshape water topology and thereby control catalytic competence in two deceptively similar P450 isozymes, providing a unified mechanistic explanation for their divergent reactivity.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"17 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2026-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146129666","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 : 2026-02-06DOI: 10.1021/acscatal.5c04841
Opeyemi A. Ojelade, Quyen Tran, Sankar Nair, Christopher W. Jones
The ketonization of carboxylic acids offers a promising pathway toward the production of valuable intermediate platform chemicals. Building on previous work involving the dehydroxylation of black liquor (BL)-derived hydroxy acids to generate a carboxylic acid-rich stream, this study explores the ketonization of (1) a model mixture comprising linear C2–C9 and branched C4–C6 acids and (2) a realistic carboxylic acid-rich mixture obtained from kraft BL, both on metal oxide catalysts. Initial screening of equimolar mixed-metal oxides ZrMOy (M = Mg, Nb, Ce, Mn) reveals ZrMnxOy as the most active and selective catalyst under varied reaction conditions. Subsequent optimization of ZrMnxOy catalysts shows that ZrMnxOy (Mn = 90 mol %) as well as Zr-free Mn3O4 delivered the highest ketonization activity, achieving up to a 10-fold activity increase compared to t-ZrO2. Mechanistic studies of C2–C9 acids show ketonization rates decline from C2–C6, then deviate nonmonotonically for C7–C9 due to steric and adsorption effects. Catalyst characterization demonstrates that increasing Mn content enhances the formation of moderate Mn2+–O2– acid–base and defect-associated lattice oxygens, which correlate with catalytic activity, and account for the strong performance of the Mn-rich catalysts. Both 90 mol % Mn and Zr-free Mn3O4 catalysts show stable ketonization performance over extended time-on-stream with minimal Mn leaching and without observable structural degradation. However, the Zr-incorporated catalyst exhibited significantly greater leaching resistance in liquid phase tests, underscoring its enhanced robustness. Using the optimized ZrMnxOy catalyst (90 mol % Mn) for the ketonization of a real BL-derived feedstock, more than 93% selectivity to mixed C3–C17 linear and branched ketones is achieved at complete acids conversion. These ketones meet the criteria for downstream condensation and hydrodeoxygenation, suggesting the viability of hydroxy acids derived from kraft BL as a feedstock for synthesis of biolubricants.
{"title":"Ketonization of Mixed Carboxylic Acid-Rich Feedstock from Kraft Black Liquor-Derived Hydroxy Acids","authors":"Opeyemi A. Ojelade, Quyen Tran, Sankar Nair, Christopher W. Jones","doi":"10.1021/acscatal.5c04841","DOIUrl":"https://doi.org/10.1021/acscatal.5c04841","url":null,"abstract":"The ketonization of carboxylic acids offers a promising pathway toward the production of valuable intermediate platform chemicals. Building on previous work involving the dehydroxylation of black liquor (BL)-derived hydroxy acids to generate a carboxylic acid-rich stream, this study explores the ketonization of (1) a model mixture comprising linear C<sub>2</sub>–C<sub>9</sub> and branched C<sub>4</sub>–C<sub>6</sub> acids and (2) a realistic carboxylic acid-rich mixture obtained from kraft BL, both on metal oxide catalysts. Initial screening of equimolar mixed-metal oxides ZrMO<sub><i>y</i></sub> (M = Mg, Nb, Ce, Mn) reveals ZrMn<sub><i>x</i></sub>O<sub><i>y</i></sub> as the most active and selective catalyst under varied reaction conditions. Subsequent optimization of ZrMn<sub><i>x</i></sub>O<sub><i>y</i></sub> catalysts shows that ZrMn<sub><i>x</i></sub>O<sub><i>y</i></sub> (Mn = 90 mol %) as well as Zr-free Mn<sub>3</sub>O<sub>4</sub> delivered the highest ketonization activity, achieving up to a 10-fold activity increase compared to t-ZrO<sub>2</sub>. Mechanistic studies of C<sub>2</sub>–C<sub>9</sub> acids show ketonization rates decline from C<sub>2</sub>–C<sub>6</sub>, then deviate nonmonotonically for C<sub>7</sub>–C<sub>9</sub> due to steric and adsorption effects. Catalyst characterization demonstrates that increasing Mn content enhances the formation of moderate Mn<sup>2+</sup>–O<sup>2–</sup> acid–base and defect-associated lattice oxygens, which correlate with catalytic activity, and account for the strong performance of the Mn-rich catalysts. Both 90 mol % Mn and Zr-free Mn<sub>3</sub>O<sub>4</sub> catalysts show stable ketonization performance over extended time-on-stream with minimal Mn leaching and without observable structural degradation. However, the Zr-incorporated catalyst exhibited significantly greater leaching resistance in liquid phase tests, underscoring its enhanced robustness. Using the optimized ZrMn<sub><i>x</i></sub>O<sub><i>y</i></sub> catalyst (90 mol % Mn) for the ketonization of a real BL-derived feedstock, more than 93% selectivity to mixed C<sub>3</sub>–C<sub>17</sub> linear and branched ketones is achieved at complete acids conversion. These ketones meet the criteria for downstream condensation and hydrodeoxygenation, suggesting the viability of hydroxy acids derived from kraft BL as a feedstock for synthesis of biolubricants.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"48 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2026-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146129466","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 : 2026-02-06DOI: 10.1021/acscatal.5c09151
Lennert A. D’ooghe, Servaas Lips, Soumya Kumar Das, Lukas C. Buelens, Alessandro Longo, Hilde Poelman, Kevin M. Van Geem, Vladimir V. Galvita
Unlocking the full potential of CO2 as a mild oxidant in propane dehydrogenation (CO2–PDH) hinges on mastering the redox chemistry of metal oxide catalysts, that are suited to activate C–H bonds, while mitigating deactivation. This work explores a Mg(5 wt % Fe,Al)Ox catalyst, synthesized as layered double hydroxide. The ensuing stabilization of oxidized iron within Mg(Fe,Al)Ox yields intricate redox dynamics during CO2–PDH. Fe-normalized time yields between 2.0 and 5.6 mmolC3H6·molFe–1·s–1 place Mg(Fe,Al)Ox among the most efficient Fe-based systems reported to date. The catalyst withstands CO2–PDH – O2 regeneration cycles without loss of initial activity. While gradual deactivation occurs across 20 h time-on-stream, the propylene selectivity stabilizes at 78.9%, underscoring the potential for prolonged operation. The intricate redox dynamics were investigated using time-resolved XAS and XRD with modulation-excitation. This approach enabled the decoding of two distinct CO2–PDH pathways. First, iron reversibly cycles between Fe3+ in a surface MgFe2O4 phase and dispersed Fe2+ species, via Fe3+⇌Fe3+/2+⇌Fe2+ transitions. This Mars-van Krevelen pathway enables carbon removal, but can also overoxidize hydrocarbons. In a parallel Langmuir–Hinshelwood pathway, these Fe2+ species, stabilized by an MgO-like environment in a likely distorted coordination, serve as highly selective sites for C–H bond activation. Although only ∼ 1% of Fe participates, it governs the catalytic performance. In contrast, irreversible Fe3+⇌Fe3+/2+⇌Fe2+ transitions lead to MgFe2O4 depletion and aggregation of FeOx, the latter promoting carbon formation. These structure–activity relationships break the long-standing code of active site identity and dynamics in Fe-based CO2–PDH catalysts, highlighting both Fe dispersion and the Fe3+/Fe2+ speciation as critical levers for optimizing performance.
{"title":"Breaking the Code of Active Sites in CO2-Assisted Propane Dehydrogenation over Mg(Fe,Al)Ox","authors":"Lennert A. D’ooghe, Servaas Lips, Soumya Kumar Das, Lukas C. Buelens, Alessandro Longo, Hilde Poelman, Kevin M. Van Geem, Vladimir V. Galvita","doi":"10.1021/acscatal.5c09151","DOIUrl":"https://doi.org/10.1021/acscatal.5c09151","url":null,"abstract":"Unlocking the full potential of CO<sub>2</sub> as a mild oxidant in propane dehydrogenation (CO<sub>2</sub>–PDH) hinges on mastering the redox chemistry of metal oxide catalysts, that are suited to activate C–H bonds, while mitigating deactivation. This work explores a Mg(5 wt % Fe,Al)O<sub><i>x</i></sub> catalyst, synthesized as layered double hydroxide. The ensuing stabilization of oxidized iron within Mg(Fe,Al)O<sub><i>x</i></sub> yields intricate redox dynamics during CO<sub>2</sub>–PDH. Fe-normalized time yields between 2.0 and 5.6 mmol<sub>C3H6</sub>·mol<sub>Fe</sub><sup>–1</sup>·s<sup>–1</sup> place Mg(Fe,Al)O<sub><i>x</i></sub> among the most efficient Fe-based systems reported to date. The catalyst withstands CO<sub>2</sub>–PDH – O<sub>2</sub> regeneration cycles without loss of initial activity. While gradual deactivation occurs across 20 h time-on-stream, the propylene selectivity stabilizes at 78.9%, underscoring the potential for prolonged operation. The intricate redox dynamics were investigated using time-resolved XAS and XRD with modulation-excitation. This approach enabled the decoding of two distinct CO<sub>2</sub>–PDH pathways. First, iron reversibly cycles between Fe<sup>3+</sup> in a surface MgFe<sub>2</sub>O<sub>4</sub> phase and dispersed Fe<sup>2+</sup> species, via Fe<sup>3+</sup>⇌Fe<sup>3+/2+</sup>⇌Fe<sup>2+</sup> transitions. This Mars-van Krevelen pathway enables carbon removal, but can also overoxidize hydrocarbons. In a parallel Langmuir–Hinshelwood pathway, these Fe<sup>2+</sup> species, stabilized by an MgO-like environment in a likely distorted coordination, serve as highly selective sites for C–H bond activation. Although only ∼ 1% of Fe participates, it governs the catalytic performance. In contrast, irreversible Fe<sup>3+</sup>⇌Fe<sup>3+/2+</sup>⇌Fe<sup>2+</sup> transitions lead to MgFe<sub>2</sub>O<sub>4</sub> depletion and aggregation of FeO<sub><i>x</i></sub>, the latter promoting carbon formation. These structure–activity relationships break the long-standing code of active site identity and dynamics in Fe-based CO<sub>2</sub>–PDH catalysts, highlighting both Fe dispersion and the Fe<sup>3+</sup>/Fe<sup>2+</sup> speciation as critical levers for optimizing performance.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"159 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2026-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146122503","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 : 2026-02-06DOI: 10.1021/acscatal.5c07148
Yueqi Kang, Qingteng Chen, Jian Liu, Bo Yang
Catalytic cracking for propylene production is a key industrial process that addresses the growing demand for propylene in the polymer industry, where improving propylene selectivity remains a central challenge. In this study, ab initio molecular dynamics (AIMD) simulations combined with free energy sampling methods were employed to investigate the reaction network of hexane cracking, with a comparative analysis of the activity and propylene selectivity over three zeolite catalysts, HZSM-5, HSAPO-34, and HSAPO-41. The results reveal that the isomerization-cracking mechanism represents the most favorable pathway for propylene formation within the reaction network. The cracking activity of hexane is primarily governed by the acid strength of the zeolite, quantified by the reaction free energy of hexene protonation; stronger acidity corresponds to higher catalytic activity. In contrast, product selectivity is predominantly determined by the zeolite topology. A key geometric descriptor of the reactant, the Φαγ angle, defined between the α- and γ-bonds, exhibits a positive linear correlation with the effective free energy barrier of the side reaction pathway. Meanwhile, the effective free energy barrier of the main propylene-forming pathway is regulated by the maximum included sphere diameter (Di) of the zeolite, which is also positively correlated with the corresponding free energy barrier. These findings provide atomic-level insights into the structure–reactivity relationship underlying catalytic cracking and offer theoretical guidance for the rational design of zeolite catalysts with enhanced activity and propylene selectivity.
{"title":"Atomistic Insights into How Zeolite Acidity and Topology Control the Activity and Propylene Selectivity in Hexane Cracking","authors":"Yueqi Kang, Qingteng Chen, Jian Liu, Bo Yang","doi":"10.1021/acscatal.5c07148","DOIUrl":"https://doi.org/10.1021/acscatal.5c07148","url":null,"abstract":"Catalytic cracking for propylene production is a key industrial process that addresses the growing demand for propylene in the polymer industry, where improving propylene selectivity remains a central challenge. In this study, <i>ab initio</i> molecular dynamics (AIMD) simulations combined with free energy sampling methods were employed to investigate the reaction network of hexane cracking, with a comparative analysis of the activity and propylene selectivity over three zeolite catalysts, HZSM-5, HSAPO-34, and HSAPO-41. The results reveal that the isomerization-cracking mechanism represents the most favorable pathway for propylene formation within the reaction network. The cracking activity of hexane is primarily governed by the acid strength of the zeolite, quantified by the reaction free energy of hexene protonation; stronger acidity corresponds to higher catalytic activity. In contrast, product selectivity is predominantly determined by the zeolite topology. A key geometric descriptor of the reactant, the Φ<sub>αγ</sub> angle, defined between the α- and γ-bonds, exhibits a positive linear correlation with the effective free energy barrier of the side reaction pathway. Meanwhile, the effective free energy barrier of the main propylene-forming pathway is regulated by the maximum included sphere diameter (Di) of the zeolite, which is also positively correlated with the corresponding free energy barrier. These findings provide atomic-level insights into the structure–reactivity relationship underlying catalytic cracking and offer theoretical guidance for the rational design of zeolite catalysts with enhanced activity and propylene selectivity.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"17 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2026-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146122500","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 : 2026-02-06DOI: 10.1021/acscatal.5c07270
Juhyun Cho, Sang Gu Ji, Jihoon Son, Mi Ji Kim, Jeonghyeon Kim, Saehyun Park, Yoon Gyeong Jo, Hyeyoung Shin, Chang Hyuck Choi, Sang-Il Choi
The free energy of hydrogen adsorption (ΔGH) is a key descriptor for hydrogen evolution reaction (HER) kinetics in acids, although it is often limited in explaining facet- and strain-dependent catalytic activity. Here, we investigate the role of tensile strain on Pt(111) surfaces, focusing on the competitive adsorption between hydrogen and water. Combining computational and experimental studies, we demonstrate that tensile strain enhances hydrogen and water adsorption, resulting in the 1.3-fold enhancement in exchange current density compared to unstrained Pt(111). Our findings suggest that the ΔGH-based HER trends may not fully capture the influence of interfacial factors under structural deformation.
{"title":"Tensile Strain on Pt(111) Boosts Hydrogen Evolution Reaction Kinetics in Acids","authors":"Juhyun Cho, Sang Gu Ji, Jihoon Son, Mi Ji Kim, Jeonghyeon Kim, Saehyun Park, Yoon Gyeong Jo, Hyeyoung Shin, Chang Hyuck Choi, Sang-Il Choi","doi":"10.1021/acscatal.5c07270","DOIUrl":"https://doi.org/10.1021/acscatal.5c07270","url":null,"abstract":"The free energy of hydrogen adsorption (Δ<i>G</i><sub><i>H</i></sub>) is a key descriptor for hydrogen evolution reaction (HER) kinetics in acids, although it is often limited in explaining facet- and strain-dependent catalytic activity. Here, we investigate the role of tensile strain on Pt(111) surfaces, focusing on the competitive adsorption between hydrogen and water. Combining computational and experimental studies, we demonstrate that tensile strain enhances hydrogen and water adsorption, resulting in the 1.3-fold enhancement in exchange current density compared to unstrained Pt(111). Our findings suggest that the Δ<i>G</i><sub><i>H</i></sub>-based HER trends may not fully capture the influence of interfacial factors under structural deformation.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"38 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2026-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146129467","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 : 2026-02-06DOI: 10.1021/acscatal.5c07598
Yashna Khakre, Smaranda C. Marinescu
Heterometallic metal–organic frameworks (MOFs) consisting of electrocatalytically active metal ions paired with relatively inactive metal ions have shown enhanced per-site activity in the form of large turnover numbers observed for the active metal, however, at the expense of lower faradaic efficiencies (FEs). This technique has been employed to construct electrocatalysts for small molecule activation transformations, such as CO2 reduction or the hydrogen evolution reactions (HER). In this study, HER-active Co metal-ions were doped into the moderately HER active Ni-triphenylenehexatiolate (NiTHT) coordination polymer backbone. The resulting series of polycrystalline Co/Ni-THT MOFs containing as low as 5% Co showed a catalytic overpotential of −256 mV vs RHE with a Tafel slope of 65 mV dec–1. A 211-fold increase in the turnover frequency per Co, compared to the Co-only analog was observed. This dramatic improvement in per-site activity is complemented by a robust overall performance, where the catalyst showed 98% FE toward H2 production and demonstrated stable operation for over 17 h of continuous electrolysis.
{"title":"Enhanced Per-Site Electrocatalytic H2 Evolving Activity of Cobalt in Co/Ni-Dithiolene-Based Heterometallic Metal–Organic Frameworks","authors":"Yashna Khakre, Smaranda C. Marinescu","doi":"10.1021/acscatal.5c07598","DOIUrl":"https://doi.org/10.1021/acscatal.5c07598","url":null,"abstract":"Heterometallic metal–organic frameworks (MOFs) consisting of electrocatalytically active metal ions paired with relatively inactive metal ions have shown enhanced per-site activity in the form of large turnover numbers observed for the active metal, however, at the expense of lower faradaic efficiencies (FEs). This technique has been employed to construct electrocatalysts for small molecule activation transformations, such as CO<sub>2</sub> reduction or the hydrogen evolution reactions (HER). In this study, HER-active Co metal-ions were doped into the moderately HER active Ni-triphenylenehexatiolate (<b>NiTHT</b>) coordination polymer backbone. The resulting series of polycrystalline Co/Ni-THT MOFs containing as low as 5% Co showed a catalytic overpotential of −256 mV vs RHE with a Tafel slope of 65 mV dec<sup>–1</sup>. A 211-fold increase in the turnover frequency per Co, compared to the Co-only analog was observed. This dramatic improvement in per-site activity is complemented by a robust overall performance, where the catalyst showed 98% FE toward H<sub>2</sub> production and demonstrated stable operation for over 17 h of continuous electrolysis.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"1 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2026-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146122502","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}