Pub Date : 2026-02-25Epub Date: 2026-01-07DOI: 10.1016/j.apcata.2026.120775
Yan Wang , Yuxi Si , Feiyue Zhang , Zhanqi Yang , Libin Liu , Yanming Hou , Hairui Lin , Zhuohan Li , Hu Li , Lele Zhang , Pengfei Xie , Youwei Cheng
Complete oxidation of propane has attracted widespread attention in the treatment of volatile organic compounds (VOCs) from Fischer-Tropsch synthesis tail gas. Pt-based catalysts have been considered highly promising catalysts for the catalytic oxidation of propane due to their high-activity. However, despite the recognized importance of the synergistic effect between Pt nanoparticles (NPs) and support materials, the detailed reaction mechanism investigation remains limited. In this work, we demonstrate that the Pt/Al2O3 catalyst exhibits improved propane catalytic performance, which is attributed to the synergistic interaction between Pt NPs and surface hydroxyl groups on the support. The improved Pt dispersion in Pt/Al2O3 catalysts with smaller Pt NPs facilitates the spillover of gaseous oxygen species and the stabilization of active sites for propane oxidation. Furthermore, in-situ DRIFTS characterization and density functional theory (DFT) calculation confirm that surface hydroxyl groups on Al2O3 effectively reduce the activation barrier for C-H bond cleavage, thereby improving the reactivity of propane molecules. This work provides a novel insight into metal-support synergy for propane oxidation, which offers strategic guidance for the rational design of efficient catalysts in hydrocarbon conversion processes.
{"title":"Size-dependent Pt dispersion and hydroxyl-assisted synergistic mechanism for propane complete oxidation over Pt/Al2O3 catalyst","authors":"Yan Wang , Yuxi Si , Feiyue Zhang , Zhanqi Yang , Libin Liu , Yanming Hou , Hairui Lin , Zhuohan Li , Hu Li , Lele Zhang , Pengfei Xie , Youwei Cheng","doi":"10.1016/j.apcata.2026.120775","DOIUrl":"10.1016/j.apcata.2026.120775","url":null,"abstract":"<div><div>Complete oxidation of propane has attracted widespread attention in the treatment of volatile organic compounds (VOCs) from Fischer-Tropsch synthesis tail gas. Pt-based catalysts have been considered highly promising catalysts for the catalytic oxidation of propane due to their high-activity. However, despite the recognized importance of the synergistic effect between Pt nanoparticles (NPs) and support materials, the detailed reaction mechanism investigation remains limited. In this work, we demonstrate that the Pt/Al<sub>2</sub>O<sub>3</sub> catalyst exhibits improved propane catalytic performance, which is attributed to the synergistic interaction between Pt NPs and surface hydroxyl groups on the support. The improved Pt dispersion in Pt/Al<sub>2</sub>O<sub>3</sub> catalysts with smaller Pt NPs facilitates the spillover of gaseous oxygen species and the stabilization of active sites for propane oxidation. Furthermore, in-<em>situ</em> DRIFTS characterization and density functional theory (DFT) calculation confirm that surface hydroxyl groups on Al<sub>2</sub>O<sub>3</sub> effectively reduce the activation barrier for C-H bond cleavage, thereby improving the reactivity of propane molecules. This work provides a novel insight into metal-support synergy for propane oxidation, which offers strategic guidance for the rational design of efficient catalysts in hydrocarbon conversion processes.</div></div>","PeriodicalId":243,"journal":{"name":"Applied Catalysis A: General","volume":"712 ","pages":"Article 120775"},"PeriodicalIF":4.8,"publicationDate":"2026-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145974698","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-25Epub Date: 2026-01-10DOI: 10.1016/j.apcata.2026.120789
A.P. Lyulyukin, Yu.V. Dubinin, V.A. Yakovlev
This work presents the synthesis and comprehensive investigation of chromium-free catalysts based on γ-Al2O3, modified with magnesium oxide (MgO) and copper oxide (CuO), intended for application in thermocatalytic fuel combustion processes under fluidized bed conditions. The preparation technology was optimized by selecting impregnation time, drying, and calcination conditions. X-ray phase analysis confirmed the formation of a spinel solid solution structure MgxAl3-xO4, which contributes to the strengthening of the carrier. Subsequent introduction of CuO into the strengthened carrier in amounts of 2–5 wt% significantly enhanced catalytic activity, reducing the temperature for achieving 50 % CO conversion to levels comparable with the industrial deep oxidation catalyst DOC. Under vibro-fluidized bed conditions and during combustion of real sewage sludge, the developed catalysts demonstrated a high burnout degree (96–97 %) and low emissions of harmful substances (CO, NOx, CH4), comparable to industrial analogs. The obtained results indicate the promise of the proposed approach for the development of effective and environmentally safe catalysts for fuel combustion in fluidized bed.
{"title":"Synthesis and investigation of Cu-containing catalysts based on spherical γ-Al2O3 strengthened with magnesium for deep oxidation in a fluidized bed","authors":"A.P. Lyulyukin, Yu.V. Dubinin, V.A. Yakovlev","doi":"10.1016/j.apcata.2026.120789","DOIUrl":"10.1016/j.apcata.2026.120789","url":null,"abstract":"<div><div>This work presents the synthesis and comprehensive investigation of chromium-free catalysts based on γ-Al<sub>2</sub>O<sub>3</sub>, modified with magnesium oxide (MgO) and copper oxide (CuO), intended for application in thermocatalytic fuel combustion processes under fluidized bed conditions. The preparation technology was optimized by selecting impregnation time, drying, and calcination conditions. X-ray phase analysis confirmed the formation of a spinel solid solution structure Mg<sub>x</sub>Al<sub>3-x</sub>O<sub>4</sub>, which contributes to the strengthening of the carrier. Subsequent introduction of CuO into the strengthened carrier in amounts of 2–5 wt% significantly enhanced catalytic activity, reducing the temperature for achieving 50 % CO conversion to levels comparable with the industrial deep oxidation catalyst DOC. Under vibro-fluidized bed conditions and during combustion of real sewage sludge, the developed catalysts demonstrated a high burnout degree (96–97 %) and low emissions of harmful substances (CO, NO<sub>x</sub>, CH<sub>4</sub>), comparable to industrial analogs. The obtained results indicate the promise of the proposed approach for the development of effective and environmentally safe catalysts for fuel combustion in fluidized bed.</div></div>","PeriodicalId":243,"journal":{"name":"Applied Catalysis A: General","volume":"712 ","pages":"Article 120789"},"PeriodicalIF":4.8,"publicationDate":"2026-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146035603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-25Epub Date: 2026-01-06DOI: 10.1016/j.apcata.2026.120772
Liuqingqing Yang , An Bao , Tingting Wang, Chenju Chen, Chunlei Zhang
The direct hydrogenation of succinic anhydride (SA) represents an efficient and industrially promising route for γ-butyrolactone (GBL) production. However, systematic studies on this reaction remain scarce in literature. The present work investigates various SiO2 supported Ni catalysts prepared via different silica sources (silica sol, silica aerogel, and sodium silicate). Results reveal that the silica source could profoundly influence the catalytic performance through modulation of nickel phases over the catalyst surface. Particularly, the silica aerogel synthesized catalyst (Ni/SiO2-SA) demonstrates balanced phyllosilicate and NiO phases, which collectively provide optimal acidity and hydrogen dissociation capability, leading to superior catalytic performance at mild conditions. During a 72 h stability test, this catalyst maintained SA conversion and GBL selectivity at 90 % and 88 %, respectively. This study elucidates the critical role of precursor selection in active phase composition and provides valuable insights for industrial catalyst design for GBL production.
{"title":"Unveiling the importance of nickel phases for selective hydrogenation of succinic anhydride to γ-butyrolactone over Ni/SiO2 catalysts: The impact of silica sources","authors":"Liuqingqing Yang , An Bao , Tingting Wang, Chenju Chen, Chunlei Zhang","doi":"10.1016/j.apcata.2026.120772","DOIUrl":"10.1016/j.apcata.2026.120772","url":null,"abstract":"<div><div>The direct hydrogenation of succinic anhydride (SA) represents an efficient and industrially promising route for γ-butyrolactone (GBL) production. However, systematic studies on this reaction remain scarce in literature. The present work investigates various SiO<sub>2</sub> supported Ni catalysts prepared via different silica sources (silica sol, silica aerogel, and sodium silicate). Results reveal that the silica source could profoundly influence the catalytic performance through modulation of nickel phases over the catalyst surface. Particularly, the silica aerogel synthesized catalyst (Ni/SiO<sub>2</sub>-SA) demonstrates balanced phyllosilicate and NiO phases, which collectively provide optimal acidity and hydrogen dissociation capability, leading to superior catalytic performance at mild conditions. During a 72 h stability test, this catalyst maintained SA conversion and GBL selectivity at 90 % and 88 %, respectively. This study elucidates the critical role of precursor selection in active phase composition and provides valuable insights for industrial catalyst design for GBL production.</div></div>","PeriodicalId":243,"journal":{"name":"Applied Catalysis A: General","volume":"712 ","pages":"Article 120772"},"PeriodicalIF":4.8,"publicationDate":"2026-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-25Epub Date: 2026-01-14DOI: 10.1016/j.apcata.2026.120792
Shan Qiao , Kaidi Liu , Xuan Zhou , Ranqing Zhang , Yunlei An , Tiejun Lin , Liangshu Zhong
The promotional effect of aluminum (Al) on Co2C-based Fischer-Tropsch to olefins (FTO) was systematically investigated. By effectively suppressing methane formation and inhibiting the secondary hydrogenation of olefins, the introduction of Al led to a significant enhancement in olefins production, and the highest selectivity of olefins was achieved at a Co: Mn: Al molar ratio of 3:1:1. Besides, the catalyst stability was also significantly improved with the addition of Al. Structural characterization revealed that Al not only accelerates the carbonization rate of cobalt and reduces the formation of metallic Co0, thereby promoting the rapid formation of Co2C nanoprisms, but also increases the relative content of Co2C. This modulation enhances the utilization efficiency of cobalt atoms. Notably, the Al promoter also effectively reduced the size of Co2C nanoparticles from 20.3 to 8.4 nm. This size reduction increased the availability of active sites for syngas conversion to olefins, which was correlated with lower methane selectivity and higher olefins selectivity, as well as improved catalytic stability during syngas conversion. This study presents a simple and effective strategy for optimizing catalytic performance, and provides insights for the rational design of efficient Co2C-based FTO catalysts.
{"title":"Aluminum-promoted Co2C-based catalysts for enhanced Fischer-Tropsch synthesis to olefins","authors":"Shan Qiao , Kaidi Liu , Xuan Zhou , Ranqing Zhang , Yunlei An , Tiejun Lin , Liangshu Zhong","doi":"10.1016/j.apcata.2026.120792","DOIUrl":"10.1016/j.apcata.2026.120792","url":null,"abstract":"<div><div>The promotional effect of aluminum (Al) on Co<sub>2</sub>C-based Fischer-Tropsch to olefins (FTO) was systematically investigated. By effectively suppressing methane formation and inhibiting the secondary hydrogenation of olefins, the introduction of Al led to a significant enhancement in olefins production, and the highest selectivity of olefins was achieved at a Co: Mn: Al molar ratio of 3:1:1. Besides, the catalyst stability was also significantly improved with the addition of Al. Structural characterization revealed that Al not only accelerates the carbonization rate of cobalt and reduces the formation of metallic Co<sup>0</sup>, thereby promoting the rapid formation of Co<sub>2</sub>C nanoprisms, but also increases the relative content of Co<sub>2</sub>C. This modulation enhances the utilization efficiency of cobalt atoms. Notably, the Al promoter also effectively reduced the size of Co<sub>2</sub>C nanoparticles from 20.3 to 8.4 nm. This size reduction increased the availability of active sites for syngas conversion to olefins, which was correlated with lower methane selectivity and higher olefins selectivity, as well as improved catalytic stability during syngas conversion. This study presents a simple and effective strategy for optimizing catalytic performance, and provides insights for the rational design of efficient Co<sub>2</sub>C-based FTO catalysts.</div></div>","PeriodicalId":243,"journal":{"name":"Applied Catalysis A: General","volume":"712 ","pages":"Article 120792"},"PeriodicalIF":4.8,"publicationDate":"2026-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145974115","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-25Epub Date: 2026-01-09DOI: 10.1016/j.apcata.2026.120788
Yicheng Yu , Shiqi Wang , Tengyue Jiang , Tianjun Zhang , Risheng Bai , Jinhang Dai , Qiming Sun
Hydrogen storage through ammonia borane (AB) methanolysis offers a promising pathway for clean energy systems but is hindered by intrinsic kinetic barriers, necessitating highly efficient catalysts. Here, we report a Ru/SAPO-34 catalyst engineered via a seed-assisted hydrothermal synthesis coupled with steam treatment, which generates abundant surface P–OH groups and optimizes the Brønsted acidity of zeolite frameworks. These phosphorylated hydroxyl sites serve as robust anchoring centers, stabilizing small Ru nanoparticles (∼2.7 nm) introduced by incipient wetness impregnation. Benefiting from the synergy between ultrasmall Ru species and finely tuned acid sites, the optimized Ru/SP34–0.8s-H2O catalyst delivers a remarkable hydrogen generation rate of 430.1 min–1 at 298 K and maintains excellent stability over ten successive cycles, surpassing most state-of-the-art catalysts. Kinetic isotope effect analyses further reveal that framework Brønsted acid sites are crucial for O–H bond activation in methanol, thereby accelerating the rate-determining step. This work not only elucidates the mechanistic role of zeolite acidity in AB methanolysis but also establishes a rational design principle for acid–metal cooperative catalysts in chemical hydrogen storage applications.
{"title":"Zeolite-integrated Brønsted acidity and metal sites for boosted hydrogen generation from ammonia borane methanolysis","authors":"Yicheng Yu , Shiqi Wang , Tengyue Jiang , Tianjun Zhang , Risheng Bai , Jinhang Dai , Qiming Sun","doi":"10.1016/j.apcata.2026.120788","DOIUrl":"10.1016/j.apcata.2026.120788","url":null,"abstract":"<div><div>Hydrogen storage through ammonia borane (AB) methanolysis offers a promising pathway for clean energy systems but is hindered by intrinsic kinetic barriers, necessitating highly efficient catalysts. Here, we report a Ru/SAPO-34 catalyst engineered via a seed-assisted hydrothermal synthesis coupled with steam treatment, which generates abundant surface P–OH groups and optimizes the Brønsted acidity of zeolite frameworks. These phosphorylated hydroxyl sites serve as robust anchoring centers, stabilizing small Ru nanoparticles (∼2.7 nm) introduced by incipient wetness impregnation. Benefiting from the synergy between ultrasmall Ru species and finely tuned acid sites, the optimized Ru/SP34–0.8s-H<sub>2</sub>O catalyst delivers a remarkable hydrogen generation rate of 430.1 min<sup>–1</sup> at 298 K and maintains excellent stability over ten successive cycles, surpassing most state-of-the-art catalysts. Kinetic isotope effect analyses further reveal that framework Brønsted acid sites are crucial for O–H bond activation in methanol, thereby accelerating the rate-determining step. This work not only elucidates the mechanistic role of zeolite acidity in AB methanolysis but also establishes a rational design principle for acid–metal cooperative catalysts in chemical hydrogen storage applications.</div></div>","PeriodicalId":243,"journal":{"name":"Applied Catalysis A: General","volume":"712 ","pages":"Article 120788"},"PeriodicalIF":4.8,"publicationDate":"2026-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145974699","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-25Epub Date: 2026-01-08DOI: 10.1016/j.apcata.2025.120767
Konrad Koschnick , Alison M. Ferris , Marcel Stark , Danny Stark , Jan Welzenbach , Nico Winkler , Andreas Weinmann , Christian Hess , Bastian J.M. Etzold , Alfons Drochner , Tanja Franken , Dirk Geyer , Andreas Dreizler
A novel optically accessible catalysis flow channel is introduced that enables quantitative, contiguous, two-dimensional in situ measurements of gas-phase temperature and species concentrations during heterogeneous catalytic reactions. Spatially resolved gas-phase Raman spectroscopy, integral Fourier-transform infrared spectroscopy, and catalyst-resolved infrared thermography establish a well-defined platform for studying coupled reaction–transport phenomena. Applied to the oxidative dehydrogenation of ethanol over iron–molybdenum oxide catalysts, spontaneous Raman measurements yielded two-dimensional profiles of nine gas-phase species – with limits of detection in the tens-to-hundreds-of-ppm range – and gas-phase temperature within 500 µm of the catalyst surface. Transport analysis in the boundary layer yielded a Lewis number of approximately 1.65, indicating dominant thermal diffusion near the surface, while axial Péclet numbers revealed diffusion-controlled heat transport but advection-dominated product transport in a laminar regime. Varying the bulk flow velocity did not significantly alter conversion or product distributions, indicating kinetic and diffusive control under the present conditions. An iron-rich catalyst formulation exhibited higher activity than stoichiometric , whereas temperatures above 511 K reduced selectivity due to increased formation of total-oxidation products. Catalyst-free experiments, supported by kinetic simulations, confirmed partial gas-phase oxidation of acetaldehyde to CO, CO2, acetic acid, methanol, formaldehyde, and peracetic acid. These results highlight the importance of local gas-phase contributions and demonstrate that spatially resolving the gas-phase thermochemistry enables the gas phase to act as a reporter of surface reactions and facilitates the decoupling of chemical processes from transport phenomena.
{"title":"Gas-phase Raman spectroscopy for two-dimensional temperature and concentration profiling in the catalytic oxidative dehydrogenation of ethanol","authors":"Konrad Koschnick , Alison M. Ferris , Marcel Stark , Danny Stark , Jan Welzenbach , Nico Winkler , Andreas Weinmann , Christian Hess , Bastian J.M. Etzold , Alfons Drochner , Tanja Franken , Dirk Geyer , Andreas Dreizler","doi":"10.1016/j.apcata.2025.120767","DOIUrl":"10.1016/j.apcata.2025.120767","url":null,"abstract":"<div><div>A novel optically accessible catalysis flow channel is introduced that enables quantitative, contiguous, two-dimensional in situ measurements of gas-phase temperature and species concentrations during heterogeneous catalytic reactions. Spatially resolved gas-phase Raman spectroscopy, integral Fourier-transform infrared spectroscopy, and catalyst-resolved infrared thermography establish a well-defined platform for studying coupled reaction–transport phenomena. Applied to the oxidative dehydrogenation of ethanol over iron–molybdenum oxide catalysts, spontaneous Raman measurements yielded two-dimensional profiles of nine gas-phase species – with limits of detection in the tens-to-hundreds-of-ppm range – and gas-phase temperature within 500<!--> <!-->µm of the catalyst surface. Transport analysis in the boundary layer yielded a Lewis number of approximately 1.65, indicating dominant thermal diffusion near the surface, while axial Péclet numbers revealed diffusion-controlled heat transport but advection-dominated product transport in a laminar regime. Varying the bulk flow velocity did not significantly alter conversion or product distributions, indicating kinetic and diffusive control under the present conditions. An iron-rich catalyst formulation exhibited higher activity than stoichiometric <figure><img></figure> , whereas temperatures above 511<!--> <!-->K reduced selectivity due to increased formation of total-oxidation products. Catalyst-free experiments, supported by kinetic simulations, confirmed partial gas-phase oxidation of acetaldehyde to CO, CO<sub>2</sub>, acetic acid, methanol, formaldehyde, and peracetic acid. These results highlight the importance of local gas-phase contributions and demonstrate that spatially resolving the gas-phase thermochemistry enables the gas phase to act as a reporter of surface reactions and facilitates the decoupling of chemical processes from transport phenomena.</div></div>","PeriodicalId":243,"journal":{"name":"Applied Catalysis A: General","volume":"712 ","pages":"Article 120767"},"PeriodicalIF":4.8,"publicationDate":"2026-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this work, an investigation of methane pyrolysis over Fe/Al-based catalysts has been carried out to optimize the formulation, that is to obtain structural features suitable to high C/Fe ratios before the catalyst is fully deactivated. At this scope, Fe-Al2O3 catalysts at different Fe-Al ratios were prepared by the fusion-decomposition method and reduction in H2; fresh and reduced samples were extensively characterized by N2 adsorption/desorption, electron microscopies, X-Ray Diffraction and Raman spectroscopy. As a general feature, the reduced catalyst structures are characterized by mesoporous Fe aggregates dispersed in microporous alumina, with presence of FeAl2O4 at the interface; however, several textural parameters (including specific surface area, pore size distribution, Fe crystallite size, FeAl2O4 abundance) change importantly with increasing Fe/Al ratio. Close to the equimolar Fe-Al ratio, such textural properties appear optimal to guarantee high Fe dispersion and accessibility. All the formulations were first screened in methane pyrolysis in a thermobalance; a selected subset of formulations was then tested in a packed bed reactor. The study reveals that formulations with Fe-Al molar ratios from 50–50 to 75–25 are all characterized by high initial activity and lower deactivation rate, thus achieving the maximum C-accumulation capacity. Among them, the equimolar formulation achieved the highest C/Fe ratio, reaching 2.5 gC/gFe after 1 h testing with 40 % CH4 at 800°C. The spent catalysts were characterized by electron microscopies, X-Ray Diffraction and Raman spectroscopy to better comprehend the effects of extent of reaction and Fe-Al ratio on the characteristics of the solid. In all the samples, after reaction, the Fe3C was the main iron-containing phase and a progressive decrease of the residual Fe phase was observed at increasing C-accumulation. Concerning the nature of C-structures, a large variety of them was observed depending on Fe content and crystalline size.
{"title":"Methane pyrolysis on fused Fe-Al2O3 catalysts: Characterization of catalyst structure, performance and carbon formation","authors":"Chiara Negri , Veronica Piazza , Marco Orsenigo, Matteo Maestri, Gianpiero Groppi, Lidia Castoldi, Alessandra Beretta","doi":"10.1016/j.apcata.2025.120719","DOIUrl":"10.1016/j.apcata.2025.120719","url":null,"abstract":"<div><div>In this work, an investigation of methane pyrolysis over Fe/Al-based catalysts has been carried out to optimize the formulation, that is to obtain structural features suitable to high C/Fe ratios before the catalyst is fully deactivated. At this scope, Fe-Al<sub>2</sub>O<sub>3</sub> catalysts at different Fe-Al ratios were prepared by the fusion-decomposition method and reduction in H<sub>2</sub>; fresh and reduced samples were extensively characterized by N<sub>2</sub> adsorption/desorption, electron microscopies, X-Ray Diffraction and Raman spectroscopy. As a general feature, the reduced catalyst structures are characterized by mesoporous Fe aggregates dispersed in microporous alumina, with presence of FeAl<sub>2</sub>O<sub>4</sub> at the interface; however, several textural parameters (including specific surface area, pore size distribution, Fe crystallite size, FeAl<sub>2</sub>O<sub>4</sub> abundance) change importantly with increasing Fe/Al ratio. Close to the equimolar Fe-Al ratio, such textural properties appear optimal to guarantee high Fe dispersion and accessibility. All the formulations were first screened in methane pyrolysis in a thermobalance; a selected subset of formulations was then tested in a packed bed reactor. The study reveals that formulations with Fe-Al molar ratios from 50–50 to 75–25 are all characterized by high initial activity and lower deactivation rate, thus achieving the maximum C-accumulation capacity. Among them, the equimolar formulation achieved the highest C/Fe ratio, reaching 2.5 g<sub>C</sub>/g<sub>Fe</sub> after 1 h testing with 40 % CH<sub>4</sub> at 800°C. The spent catalysts were characterized by electron microscopies, X-Ray Diffraction and Raman spectroscopy to better comprehend the effects of extent of reaction and Fe-Al ratio on the characteristics of the solid. In all the samples, after reaction, the Fe<sub>3</sub>C was the main iron-containing phase and a progressive decrease of the residual Fe phase was observed at increasing C-accumulation. Concerning the nature of C-structures, a large variety of them was observed depending on Fe content and crystalline size.</div></div>","PeriodicalId":243,"journal":{"name":"Applied Catalysis A: General","volume":"711 ","pages":"Article 120719"},"PeriodicalIF":4.8,"publicationDate":"2026-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145617330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-05Epub Date: 2025-12-10DOI: 10.1016/j.apcata.2025.120743
E. Amaterz , O. Bajouk , B. Ravi , I. Rougeaux , R. Ramos , V. Faucheux , P. Chenevier
In this study, Ag structures with tunable morphologies were synthesized via different methods and evaluated for the electrochemical CO2 reduction (CO2RR) in both H-cell and zero-gap electrolyzer configurations. Scanning electron microscopy (SEM) confirmed that the Ag catalysts could be tuned to exhibit distinct morphologies, such as polygonal, flower-like, nanowires and rod-like structures. Among these, the rod-like Ag (Ag-Rod) catalyst exhibited the highest Faradaic efficiency for CO (>96 %), demonstrating excellent selectivity in both configurations. In-situ surface-enhanced Raman spectroscopy (SERS) was adopted to monitor the adsorption of reaction intermediates in real time, revealing dynamic changes in CO-related species and other adsorbates as a function of applied potential. The enhanced SERS response arising from the plasmonic properties of Ag enabled the direct observation of key reaction intermediates. The results show that the rod-like Ag structure exhibits superior CO selectivity, which is attributed to its morphology-dependent surface properties and favorable CO desorption dynamics. These findings highlight the critical role of structural tuning in governing CO2RR pathways, providing mechanistic insight into how morphology and plasmonic effects can be leveraged to design efficient and selective Ag-based electrocatalysts for CO2 conversion.
{"title":"Tailoring silver nanostructures for enhanced CO2 reduction: Insights from In-situ SERS and electrochemical studies","authors":"E. Amaterz , O. Bajouk , B. Ravi , I. Rougeaux , R. Ramos , V. Faucheux , P. Chenevier","doi":"10.1016/j.apcata.2025.120743","DOIUrl":"10.1016/j.apcata.2025.120743","url":null,"abstract":"<div><div>In this study, Ag structures with tunable morphologies were synthesized via different methods and evaluated for the electrochemical CO<sub>2</sub> reduction (CO<sub>2</sub>RR) in both H-cell and zero-gap electrolyzer configurations. Scanning electron microscopy (SEM) confirmed that the Ag catalysts could be tuned to exhibit distinct morphologies, such as polygonal, flower-like, nanowires and rod-like structures. Among these, the rod-like Ag (Ag-Rod) catalyst exhibited the highest Faradaic efficiency for CO (>96 %), demonstrating excellent selectivity in both configurations. <em>In-situ</em> surface-enhanced Raman spectroscopy (SERS) was adopted to monitor the adsorption of reaction intermediates in real time, revealing dynamic changes in CO-related species and other adsorbates as a function of applied potential. The enhanced SERS response arising from the plasmonic properties of Ag enabled the direct observation of key reaction intermediates. The results show that the rod-like Ag structure exhibits superior CO selectivity, which is attributed to its morphology-dependent surface properties and favorable CO desorption dynamics. These findings highlight the critical role of structural tuning in governing CO<sub>2</sub>RR pathways, providing mechanistic insight into how morphology and plasmonic effects can be leveraged to design efficient and selective Ag-based electrocatalysts for CO<sub>2</sub> conversion.</div></div>","PeriodicalId":243,"journal":{"name":"Applied Catalysis A: General","volume":"711 ","pages":"Article 120743"},"PeriodicalIF":4.8,"publicationDate":"2026-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-05Epub Date: 2025-12-25DOI: 10.1016/j.apcata.2025.120760
Juan J. Giraldo , Juliana Perez Espinoza , Cristian Díaz , Diana López , Sébastien Royer , Camila A. Teles , Frédéric Richard , Ruben Palacio
In this work, a series of bimetallic NiFe catalysts supported on SBA-15 silica and ZrO2/SBA-15 were synthesized for the hydrodeoxygenation of guaiacol with the aim of evaluating the chemical composition, Ni:Fe ratio, electronic properties of NiFe and solvent nature impact on conversion and selectivity. In hexadecane solvent at 300 ºC, catalysts containing ZrO2, Ni8.2Fe1.6-ZrO2/SBA-15 and Ni8.3Fe0.7-ZrO2/SBA-15, achieved high guaiacol conversion of 99.0 ± 0.5 % after 5 h of reaction and were selective toward cyclohexane, 23.2 % and 50.6 % respectively, but suffer from low carbon balance. For catalysts without ZrO2, Ni13.3Fe1.3/SBA-15 and Ni4.7Fe0.5/SBA-15, the conversion of guaiacol reached 84.8 ± 0.5 %, but the main product was cyclohexanol, reaching 91.5 % selectivity with Ni4.7Fe0.5/SBA-15 catalyst, and with high carbon balance of 96.5 % indicating low by-product/coke formation. At 250 ºC, the Ni4.7Fe0.5/SBA-15 catalyst reached a guaiacol conversion of 73.7 % and cyclohexanol selectivity of 57.3 %. This material exhibits nanoparticles (5.2 nm) with Ni and Fe in close contact, confined inside the mesopores of the SBA-15, and is the one showing the highest surface concentration of reduced nickel (Ni0). Results also showed that Fe3+ species modified the electronic structure of Ni0, that resulted in improved conversion and product selectivity compared to monometallic Ni-containing catalysts which exhibited lower catalytic activity. Using water as a solvent at 250 ºC resulted in a lower guaiacol conversion (36.5 % after 8 h under H2) but favored selectivity toward aromatics: catechol and phenol while retaining satisfying carbon balance (67.5 %).
{"title":"Bimetallic NiFe confined in SBA-15 for efficient guaiacol hydrodeoxygenation","authors":"Juan J. Giraldo , Juliana Perez Espinoza , Cristian Díaz , Diana López , Sébastien Royer , Camila A. Teles , Frédéric Richard , Ruben Palacio","doi":"10.1016/j.apcata.2025.120760","DOIUrl":"10.1016/j.apcata.2025.120760","url":null,"abstract":"<div><div>In this work, a series of bimetallic NiFe catalysts supported on SBA-15 silica and ZrO<sub>2</sub>/SBA-15 were synthesized for the hydrodeoxygenation of guaiacol with the aim of evaluating the chemical composition, Ni:Fe ratio, electronic properties of NiFe and solvent nature impact on conversion and selectivity. In hexadecane solvent at 300 ºC, catalysts containing ZrO<sub>2</sub>, Ni<sub>8.2</sub>Fe<sub>1.6</sub>-ZrO<sub>2</sub>/SBA-15 and Ni<sub>8.3</sub>Fe<sub>0.7</sub>-ZrO<sub>2</sub>/SBA-15, achieved high guaiacol conversion of 99.0 ± 0.5 % after 5 h of reaction and were selective toward cyclohexane, 23.2 % and 50.6 % respectively, but suffer from low carbon balance. For catalysts without ZrO<sub>2</sub>, Ni<sub>13.3</sub>Fe<sub>1.3</sub>/SBA-15 and Ni<sub>4.7</sub>Fe<sub>0.5</sub>/SBA-15, the conversion of guaiacol reached 84.8 ± 0.5 %, but the main product was cyclohexanol, reaching 91.5 % selectivity with Ni<sub>4.7</sub>Fe<sub>0.5</sub>/SBA-15 catalyst, and with high carbon balance of 96.5 % indicating low by-product/coke formation. At 250 ºC, the Ni<sub>4.7</sub>Fe<sub>0.5</sub>/SBA-15 catalyst reached a guaiacol conversion of 73.7 % and cyclohexanol selectivity of 57.3 %. This material exhibits nanoparticles (5.2 nm) with Ni and Fe in close contact, confined inside the mesopores of the SBA-15, and is the one showing the highest surface concentration of reduced nickel (Ni<sup>0</sup>). Results also showed that Fe<sup>3+</sup> species modified the electronic structure of Ni<sup>0</sup>, that resulted in improved conversion and product selectivity compared to monometallic Ni-containing catalysts which exhibited lower catalytic activity. Using water as a solvent at 250 ºC resulted in a lower guaiacol conversion (36.5 % after 8 h under H<sub>2</sub>) but favored selectivity toward aromatics: catechol and phenol while retaining satisfying carbon balance (67.5 %).</div></div>","PeriodicalId":243,"journal":{"name":"Applied Catalysis A: General","volume":"711 ","pages":"Article 120760"},"PeriodicalIF":4.8,"publicationDate":"2026-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145836470","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The efficient utilization of red light, which is characterized by its relatively low energy, minimal health risks, high penetration depth in the reaction medium, and high abundance in the solar spectrum, represents a significant and challenging task in the field of organic transformations. In this study, a novel composite consisting of lead-free Cs3Bi2Br9 (CBB) perovskite and PCN-224 was successfully synthesized and comprehensively characterized through a series of standard techniques. The as-designed CBB/PCN-224 heterojunction exhibits remarkable catalytic activity for the red-light-induced acetylation of aryl diazonium salts with acetonitrile. In this reaction, acetonitrile serves as the acylating agent, and the entire process can be carried out at room temperature. This mild synthetic protocol features a broad substrate scope, enabling the synthesis of a wide range of N-arylacetamides with high to excellent yields. Furthermore, the CBB/PCN-224 composite demonstrates good recyclability. It can be reused for up to five consecutive reaction cycles without a significant loss of its photocatalytic activity, highlighting its potential for practical applications in photo-redox chemical reactions.
{"title":"Near-infrared light-driven synthesis of N-arylacetamides over Cs3Bi2Br9 perovskite/PCN-224","authors":"Shuai-Zheng Zhang, Jia-Hao Li, Ming-Ming Li, Zhan-Hui Zhang","doi":"10.1016/j.apcata.2025.120763","DOIUrl":"10.1016/j.apcata.2025.120763","url":null,"abstract":"<div><div>The efficient utilization of red light, which is characterized by its relatively low energy, minimal health risks, high penetration depth in the reaction medium, and high abundance in the solar spectrum, represents a significant and challenging task in the field of organic transformations. In this study, a novel composite consisting of lead-free Cs<sub>3</sub>Bi<sub>2</sub>Br<sub>9</sub> (CBB) perovskite and PCN-224 was successfully synthesized and comprehensively characterized through a series of standard techniques. The as-designed CBB/PCN-224 heterojunction exhibits remarkable catalytic activity for the red-light-induced acetylation of aryl diazonium salts with acetonitrile. In this reaction, acetonitrile serves as the acylating agent, and the entire process can be carried out at room temperature. This mild synthetic protocol features a broad substrate scope, enabling the synthesis of a wide range of <em>N</em>-arylacetamides with high to excellent yields. Furthermore, the CBB/PCN-224 composite demonstrates good recyclability. It can be reused for up to five consecutive reaction cycles without a significant loss of its photocatalytic activity, highlighting its potential for practical applications in photo-redox chemical reactions.</div></div>","PeriodicalId":243,"journal":{"name":"Applied Catalysis A: General","volume":"711 ","pages":"Article 120763"},"PeriodicalIF":4.8,"publicationDate":"2026-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145880359","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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