Article
Nanoscience & Nanotechnology
Lin-Yu Zhou, Shao-Bo Cao, Liang-Liang Zhang, Guolei Xiang, Xiao-Fei Zeng, Jian-Feng Chen
Summary: Supports can regulate the atomic geometry and electronic structures of active sites at the interface, thus affecting the catalytic activity and selectivity of nanoparticles. In this study, we constructed the Co3O4/TiO2 interface to enhance the catalytic decomposition of ammonium perchlorate (AP). Experimental and theoretical studies revealed that Co3O4 nanoparticles can strongly anchor onto TiO2 supports with charge transfer, leading to enhanced NH3 adsorption through hydrogen bonds at the interface. These findings provide new insights into the promotion effects of the nanoparticle/support system on the AP decomposition process and inspire efficient catalyst design.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Physical
Ester Gutierrez-Acebo, Jerome Rey, Christophe Bouchy, Yves Schuurman, Celine Chizallet
Summary: The mechanism and kinetics of the transformation of ethylcyclohexane using a bifunctional catalyst of platinum and EU-1 zeolite were studied through experiments, DFT calculations, and microkinetic modeling. The mechanism involves carbenium intermediates with pi-complexes playing a central kinetic role. The agreement between the DFT-based microkinetic model and experimental data was very good, confirming the relevance of the proposed mechanisms and computed rate constants.
Article
Nanoscience & Nanotechnology
Xi Chen, Jiaqiang Yang, Zhang Liu, Yanwei Wen, Rong Chen, Shiying Chang, Aimin Zhang, Chun Du, Bin Shan
Summary: Based on first-principles calculations and micro kinetic analysis, this study systematically investigates the reaction routes and origin of the activity of SmMn2O5 mullite for the selective catalytic oxidation of ammonia (NH3-SCO) under experimentally operating conditions. The study identifies the key influencing factors and contributions of different iconic intermediate species to the overall reaction process. It is found that Mn4+ serves as the primary active site for NH3 adsorption, while lattice oxygen participates in the dehydrogenation of NH3 on specific surfaces. Additionally, the study highlights the synergy effect of exposed Mn???Mn dimers and the most labile O2 atoms on a specific surface, leading to the highest activity and N2 selectivity at low temperatures. Furthermore, doping with La, Pr, and Nd is predicted to enhance the catalytic performance.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Multidisciplinary
Baolin Mu, Xianjuan Zhang, Yexin Zhang, Peng Lu, Jianying Hao, Jian Zhang
Summary: Fabricating oxygen vacancy-rich Co3O4 catalysts through solution combustion method provides high activity and durability for formaldehyde elimination.
Article
Chemistry, Physical
Fabian Morteo-Flores, Max Quayle, Antoni Salom-Catala, Marc Pera-Titus, Alberto Roldan Martinez
Summary: A first-principles microkinetic model was constructed to investigate the mechanism behind the hydrodeoxygenation of guaiacol on different metal surfaces. The demethylation of guaiacol to catechol on Ni(111) was found to be the most energetically favorable pathway, showing desirable deoxygenation and hydrogenation kinetics at industrial temperatures. Although guaiacol readily undergoes hydrogenation on Pt(111) and Pd(111), the products desorb slowly from the surfaces at standard operation temperatures, and the deoxygenation pathway is hindered by a high energy barrier associated with the scission of the Calkyl-O bond.
Article
Engineering, Environmental
Haipeng Yu, Lingtao Wang, Yingzhe Yu, Guochao Yang, Minhua Zhang
Summary: In this study, a comprehensive reaction network analysis on the Co2C(1 1 1) facet was conducted using first-principles-based microkinetics modeling. Pathways for generating methane, ethane, ethylene, acetaldehyde, ethanol, and C3+ products were identified, and the predicted product distribution matched experimental observations. The competition between hydrocarbon and oxygenate formation was analyzed, and the elementary reaction steps controlling product selectivity were quantitatively determined.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Engineering, Environmental
Shangfeng Li, Hao Yan, Yibin Liu, Xiaobo Chen, Xin Zhou, Xiang Feng, Chaohe Yang
Summary: Metal doped ZSM-5 catalysts have been extensively studied for their unique catalytic activity in C-H bond activation. In this work, we used density functional theory calculations and microkinetic analysis to explore the catalytic activity of 12 transition metal single-atom-doped ZSM-5 zeolite catalysts in the catalytic cracking of naphtha. Our results show a strong electronic interaction between the metal atom and ZSM-5 skeleton, leading to a stable structure that enhances hydrocarbon adsorption and promotes C-H bond activation and carbenium ion cracking. Carbon and hydrogen binding energy were identified as descriptors for catalytic activity.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Chemistry, Physical
Maximilian Kastenmeier, Lukas Fusek, Fatema Mohamed, Christian Schuschke, Michal Ronovsky, Matteo Farnesi Camellone, Nataliya Tsud, Viktor Johanek, Stefano Fabris, Simone Piccinin, Josef Myslivec, Olaf Brummel, Yaroslava Lykhach, Tomas Skala, Joerg Libuda
Summary: The formation of the metal-oxide interface in the Pd/Co3O4(111) model catalyst was investigated using DFT, SRPES, and STM. The interaction between the metal and support led to charge transfer and the formation of atomically dispersed Pd2+ species and partially oxidized Pd delta + aggregates. The most energetically favorable configuration was atomically dispersed Pd2+ species on the Co3O4(111) surface. The partially oxidized Pd delta + and Pd4Ox aggregates served as nuclei for the growth of metallic Pd0 nanoparticles.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Engineering, Environmental
Meng Wang, Xiaowei Hong, Jianjun Chen, Junhua Li, Xiaoping Chen, Jinxing Mi, Zhiming Liu, Shangchao Xiong
Summary: MnOx-CeO2 catalysts prepared by either a two-step hydrothermal method or a deposition-precipitation method were evaluated for formaldehyde oxidation. The catalyst prepared by the hydrothermal method showed higher activity, which was attributed to the higher contents of Ce3+ and Mn4+ species and the generation of abundant chemisorbed oxygen species. DFT simulation confirmed the results and revealed the role of Mn loading on the CeO2 (1 1 0) plane.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Biochemistry & Molecular Biology
Yibo Feng, Jiaxing Wang, Jixiang Hou, Xu Zhang, Yuhang Gao, Kaiwen Wang
Summary: Surface-enhanced Raman spectroscopy (SERS) is an ultra-sensitive and rapid technique that significantly enhances the Raman signals of analytes absorbed on functional substrates. Recently, semiconductor-based SERS substrates have shown rapid progress due to their cost-effectiveness, stability, and biocompatibility. In this study, different forms of Co3O4 microcrystals were utilized as SERS substrates for detecting specific molecules. C-100 showed the highest SERS sensitivity and the lowest detection limits to the molecules tested. First-principles density functional theory (DFT) simulations revealed a stronger photoinduced charge transfer (PICT) in C-100 compared to C-111.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2022)
Article
Chemistry, Physical
Dongxiao Chen, Pei-Lin Kang, Zhi-Pan Liu
Summary: By using machine-learning reaction exploration, it was found that ethene oxidation on silver metal surfaces has three low-energy pathways, with the dehydrogenation of oxometallacycle intermediate (OMC-DH) being the most important one. The dominance of the dehydrogenation path for ethene oxidation on both Ag(100) and Ag(111) metal surfaces regardless of the reaction conditions rationalizes the low selectivity to combustion products in low oxygen pressure experiments. The presence of the OMC-DH pathway and the general low selectivity on metal sites were confirmed by evaluating this mechanism on different catalysts, pointing towards revealing the true active site of Ag-based catalyst in ethene oxidation.
Article
Chemistry, Physical
Samantha Francis, Alexandre Boucher, Glenn Jones, Alberto Roldan
Summary: In this study, the digestion and growth mechanism of gold clusters on MgO surface were investigated using ab-initio calculations and microkinetic simulations. A unique cluster trend and the temperature range of presence of single atoms on the surface were identified.
APPLIED SURFACE SCIENCE
(2022)
Article
Chemistry, Physical
Huixian Liu, Liwen Li, Yuyao Qin, Hua Wang, Xinli Zhu, Qingfeng Ge
Summary: The mechanism of methane to methanol on CuOx surfaces was studied using density functional theory calculations. It was found that selective oxidation of methane to methanol occurs at the Cu-O site, and methanol formation from dissociated CH3 and H can take place over either Cu-O or O-O site. On CuO(111), the synergistic effect of methane activation at the Cu-O site and methanol formation over the O-O site enables the selective oxidation of methane to methanol. Methanol formation on O-deficient surfaces, on the other hand, results from the direct coupling of CH3 on Cu and OH formed from H adsorbed on the surface O site. Microkinetics analysis confirmed the synergistic effect of Cu-O and O-O on CuO(111) for methanol formation in a temperature range of 473-648 K. These findings demonstrate the feasibility of selective oxidation of methane to methanol with the surface lattice oxygen of CuOx and help to design CuOx-based oxygen carriers and/or catalysts.
APPLIED SURFACE SCIENCE
(2023)
Article
Engineering, Environmental
Mugdha Ambast, Sotirios A. Malamis, Michael P. Harold
Summary: The study reports the effects of C12H26 on NO uptake and release mechanisms in a Pd/SSZ-13-coated PNA monolith. Pre-adsorbed C12H26 may block NO access to pores, decreasing available sites for NO uptake. Furthermore, oxidation of C12H26 can delay NO release by forming CO which binds strongly to Pd sites.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Chemistry, Physical
Muhua Chen, Weizhen Wang, Yuping Qiu, He Wen, Guangyao Li, Zhiqing Yang, Ping Wang
Summary: This study experimentally identified the active sites in HCHO oxidation over TiO2-supported Pt catalysts and revealed the cooperative mechanism involved.
Article
Chemistry, Applied
Qingyuan Zheng, Jack H. Williams, Scott Elgersma, Mick D. Mantle, Andrew J. Sederman, G. Leendert Bezemer, Constant M. Guedon, Lynn F. Gladden
Summary: In this study, a pilot-scale fixed-bed reactor compatible with NMR/MRI was developed for Fischer-Tropsch synthesis. Multiple magnetic resonance techniques were applied to quantitatively characterize different product species within catalyst pellets, providing valuable information for catalyst and reactor optimization.
Article
Chemistry, Applied
Lisa Ramisch, Sebastian Pfaff, Sabrina M. Gericke, Edvin Lundgren, Johan Zetterberg
Summary: We present a combination of optical operando techniques that allow simultaneous measurement of adsorbed species on catalyst surfaces, monitoring of surface oxide formation, and imaging of the gas phase above the catalyst surface. The experimental setup was validated by studying CO oxidation on Pd(100) at different pressures, revealing the effects of pressure on the heterogeneous catalytic reaction.
Article
Chemistry, Applied
Marta Paniagua, Gabriel Morales, Juan A. Melero, Daniel Garcia-Salgado
Summary: The influence of common impurities in levulinic acid on the catalytic performance of different acid catalysts for bio-jet fuel production was studied. It was found that furfural had the greatest detrimental effect on catalyst performance, while propyl-sulfonic acid-modified SBA-15 and sulfonic acid resin Amberlyst-70 showed good regeneration ability.
Article
Chemistry, Applied
Jesus Tapiador, Pedro Leo, Guillermo Calleja, Gisela Orcajo
Summary: This study presents a new MOF material, Zn-URJC-13, with acid and basic sites, permanent porosity, and high affinity to CO2 molecules. The Zn-URJC-13 catalyst exhibits efficient performance in CO2 cycloaddition reactions and can be reused multiple times.
Article
Chemistry, Applied
Dan Zhao, Vita A. Kondratenko, Dmitry E. Doronkin, Shanlei Han, Jan-Dierk Grunwaldt, Uwe Rodemerck, David Linke, Evgenii V. Kondratenko
Summary: This study demonstrates the potential of cheap and commercially available Zr or Ti-based supports and ZnO to serve as active and selective catalysts for propane dehydrogenation (PDH). The catalytically active species formed in situ under PDH conditions consist of isolated ZnOx. ZnOx on the surface of LaZrOx shows the highest rate of propene formation.
Article
Chemistry, Applied
Hanbyeol Kim, Jung Rae Kim, Young-Kwon Park, Jeong-Myeong Ha, Jungho Jae
Summary: In this study, metal phosphates were used as catalysts for biomass conversion to produce sustainable aromatics through DielsAlder cycloaddition reactions. The effects of synthesis method, activation method, and P/Ti molar ratio on the structure and acid properties of titanium phosphate catalysts were systematically studied. The mesoporous titanium phosphate catalyst synthesized by hydrothermal method at 180℃ for 12 h followed by ethanol refluxing at 60℃ for 24 h at a molar P/Ti ratio of 1 showed the highest surface area and acid site density.
Article
Chemistry, Applied
Yasin Khani, Sumin Pyo, Kwang-Eun Jeong, Chul-Ung Kim, Moonis Ali Khan, Byong-Hun Jeon, Kun-Yi Andrew Lin, Siyoung Q. Choi, Young-Kwon Park
Summary: A protonated form of Zeolite Socony Mobil-5 (H-ZSM-5) catalyst was synthesized through a hydrothermal method using different sources of silica. The effect of loading the catalyst with yttrium, samarium, and gadolinium on the acidic properties was investigated. Among the metal-loaded catalysts, the Sm/LHZ catalyst showed the best performance in the methanol to propylene conversion due to its high amount of weak and intermediate acid sites, while the Gd-LHZ catalyst increased the selectivity towards ethane and propane.
Article
Chemistry, Applied
Michael Franc, Ivana Cisarova, Jan Vesely
Summary: The present study investigates an enantioselective cyclization of enals with imidazolone derivatives catalyzed by a combination of achiral Pd(0) complex and chiral secondary amine. Corresponding spirocyclic imidazolones were produced in high yields with moderate diastereoselectivity and excellent enantioselectivity. The developed co-operative catalytic methodology provides a highly substituted spirocyclic scaffold with four stereogenic centers under mild conditions.
Article
Chemistry, Applied
Mauro Alvarez, Jennifer Cueto, David P. Serrano, Pablo Marin, Salvador Ordonez
Summary: This study focuses on improving the formulation and preparation methods of catalysts for the production of dimethyl carbonate. By using suitable catalyst preparation methods and copper salt precursors, the researchers successfully produced catalysts with optimal performance for dimethyl carbonate formation.
Article
Chemistry, Applied
Claudia J. Keijzer, Luc C. J. Smulders, Dennie Wezendonk, Jan Willem de Rijk, Petra E. de Jongh
Summary: This study investigates the catalytic behavior of alpha-alumina supported silver catalysts in the presence of chloride. It is found that the particle size of silver can affect the selectivity of the catalyst, but different strategies lead to different results. In this size range, the selectivity of ethylene oxide is correlated to the Ag : Al2O3 surface ratio.
Article
Chemistry, Applied
Takeshi Aihara, Wataru Aoki, Michikazu Hara, Keigo Kamata
Summary: The development of acid-base bifunctional catalysts is important for promoting specific chemical transformations. In this study, Ti-based perovskite oxides were synthesized and used as catalysts for two C-C bond-forming reactions (cyanosilylation and Knoevenagel condensation). The highly pure SrTiO3 nanoparticles with a high specific surface area exhibited the highest catalytic performance, and could be easily recovered and reused.
Article
Chemistry, Applied
Olga Gorlova, Petra Pribylova, Eliska Vyskocilova, Katerina Peroutkova, Jan Kohout, Iva Paterova
Summary: This study investigates the Baeyer-Villiger oxidation of beta-cyclocitral using tin-modified mixed oxides as catalysts. The optimal reaction conditions and the effects of various factors on the reaction course and selectivity were determined. The results show that tin-modified mixed oxides exhibit high activity and selectivity in the oxidation reaction.
Article
Chemistry, Applied
M. I. Avila, M. M. Alonso-Doncel, L. Briones, G. Gomez-Pozuelo, J. M. Escola, D. P. Serrano, A. Peral, J. A. Botas
Summary: The catalytic fast pyrolysis of lignin using ion-exchanged zeolite catalysts showed significant improvements in bio-oil quality and the production of aromatic hydrocarbons and oxygenated compounds.
Article
Chemistry, Applied
Enrico Catizzone, Giorgia Ferrarelli, Paolo Bruno, Girolamo Giordano, Massimo Migliori
Summary: The acid-catalysed alcohol conversion reaction is a promising route for de-fossilization strategies. Research on pure alcohol conversion and simultaneous dehydration of mixed alcohols have shown different product compositions, with the type and distribution of acid sites affecting the reaction mechanism.
Article
Chemistry, Applied
Alireza Ranjbari, Juho Kim, Jihee Yu, Jiyun Kim, Mireu Park, Nayoung Kim, Kristof Demeestere, Philippe M. Heynderickx
Summary: This study investigated a novel kinetic model for the adsorption and photocatalytic degradation of methyl orange using commercial ZnO and reduced ZnO photocatalysts. The results provided new insights into the interaction of catalysts with molecules of different charges and compared with a previous study on methylene blue. The presence of oxygen vacancies in ZnO and their effects on adsorption and photocatalytic degradation were analyzed, and the photocatalytic degradation rate of reduced ZnO was found to increase significantly.