Article
Chemistry, Physical
Zichun Wang, Yijiao Jiang, Wenjie Yang, Ang Li, Michael Hunger, Alfons Baiker, Jun Huang
Summary: Selective aerobic oxidation of n-butane is a complex reaction with great importance in the chemical industry for producing maleic anhydride. By tuning the VOx structures in the catalyst, the activity of the reaction can be improved. The interaction between VOx single sites and surface penta-coordinated Al sites is identified as the active site promoting the reaction.
JOURNAL OF CATALYSIS
(2022)
Article
Chemistry, Physical
Ran Zhu, Bowei Liu, Siwen Wang, Xinlei Huang, Robson L. Schuarca, Wenlin He, Viktor J. Cybulskis, Jesse Q. Bond
Summary: The study focuses on the oxidative scission of 3-methyl-2-butanone over solid oxides in the gas phase, investigating the mechanisms on reducible vanadium oxides and non-reducible aluminum oxides. Insights from kinetic analysis and spectroscopic methods provide a proposed mechanism for the gas-phase oxidative scission of ketones on VOx/c-Al2O3, involving Mars-van Krevelen and Eley-Rideal pathways, and highlighting the significance of acid-base and redox steps in facilitating the oxidative scission of ketones.
JOURNAL OF CATALYSIS
(2021)
Article
Chemistry, Inorganic & Nuclear
Tianjiao Zhang, Xiubiao Ma, Jiawei Cao, Jingyu Gong, Wenchun Jiang, Huaixiang Cao, Yongqiang Wang
Summary: A series of 3DOM cerium-based perovskite catalysts with different B-site elements (Cr, Ni, and Mn) were prepared. The catalyst with Mn as the B-site element exhibited a high-quality macropore structure and large specific surface area. It showed the highest adsorption oxygen content and demonstrated the best catalytic performance in the oxidation of toluene, with good stability and a degradation rate of over 85% for more than 20 hours at 200 degrees C.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Physical
Kai Zhang, Wenhuan Wang, Honglei Ding, Junchi Ma, Yuetong Zhao, Jie Song, Ziyi Zhang, Weiguo Pan
Summary: This study systematically investigates the relationship between the structure and catalytic performance of AMn(2)O(5) mullite catalysts. The results show that the morphology and redox properties of the catalyst strongly depend on the A-site elements, and the cationic effects of the different A-sites have a significant impact on the catalytic activity. SmMn2O5 catalyst exhibits the highest activity due to its higher Mn4+/Mn3+ molar ratio, abundant Oads content, and other advantages. The preparation method of the catalyst and the addition of active agent F-127 also play an important role in the catalyst's activity.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Energy & Fuels
Changyifan Ren, Zhiwei Ge, Mingchuan Zhao, Ruoyu Wang, Lei Huang, Liejin Guo
Summary: The experimental study on supercritical water partial oxidation (SCWPO) of ethanol showed that increasing temperature and decreasing feed concentration significantly promoted gas yield and carbon gasification efficiency (CE). CE and gas yield increased with reaction time before 60 s, and stabilized between 120 s and 180 s. The proposed detailed SCWPO mechanism of ethanol provides insights into the gasification process and efficiency.
Article
Chemistry, Physical
Fan Lin, Tahrizi Andana, Yiqing Wu, Janos Szanyi, Yong Wang, Feng Gao
Summary: N2O decomposition on Cu, Co, and Fe-exchanged SSZ-13 zeolite catalysts follows a dual-site mechanism or a single-site mechanism. The reaction is limited by N-O cleavage under low pressure and first-order kinetic regime. Fe-SSZ-13 exhibits lower activation barriers, leading to a higher N2O decomposition rate.
JOURNAL OF CATALYSIS
(2021)
Article
Engineering, Chemical
Zhineng Tan, Guoli Fan, Yanyan Wang, Feng Li
Summary: In this study, a new copper nanocatalyst supported on a defect-rich MnOx matrix was developed using a modified coprecipitation method. The use of a microliquid-film reactor promoted the dispersion of copper particles and the formation of defect-rich MnOx support. The as-fabricated Cu/MnOx catalyst showed higher yield and greater stability, compared to catalysts produced using traditional methods.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2023)
Article
Engineering, Chemical
Zhineng Tan, Guoli Fan, Yanyan Wang, Feng Li
Summary: This study developed a new copper nanocatalyst supported on a defect-rich MnOx matrix for the conversion of ethanol into high-value chemicals. The use of a microliquid-film reactor promoted the dispersion of copper particles and the formation of a defect-rich MnOx support, resulting in a higher yield of acetaldehyde and greater structural stability compared to traditional catalysts. The novel synthesis strategy presented in this work enables the creation of active surface-interface structures, leading to exceptional catalytic properties for various advanced processes.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2023)
Article
Chemistry, Multidisciplinary
Chao Wang, Wei Liu, Mingzheng Liao, Jiahong Weng, Jian Shen, Ying Chen, Yanping Du
Summary: This paper reports the application of high entropy oxides (HEO) in ethanol steam reforming (ESR) and the characterization of a spinel-phase nano structure HEO. The results show that an abundance of oxygen vacancies were formed in the HEO and the metals spilled out as active species for hydrogen production during ESR. The HEO also exhibited a high thermal stability and achieved a high hydrogen yield and selectivity. This research offers possibilities for thermal catalytic hydrogen production under high temperature conditions.
Article
Chemistry, Multidisciplinary
Mohammad Bagher Askari, Hadi Beitollahi, Antonio Di Bartolomeo
Summary: Recently, the synthesis of a three-component catalyst consisting of zirconium oxide (ZrO2), nickel oxide (NiO), and reduced graphene oxide (rGO) in the form of ZrO2/NiO/rGO has been achieved by a simple one-step hydrothermal method. The catalyst exhibited excellent methanol and ethanol electrooxidation abilities with high current densities and cyclic stabilities, making it an attractive option for anode materials in alcoholic fuel cells. The detailed characterization and electrochemical tests demonstrate the outstanding capability of this new nanocatalyst.
Article
Chemistry, Physical
Mengjie Fan, Yichen Ji, Ajibola Lawal, Omar A. Abdelrahman, Raymond J. Gorte, John M. Vohs
Summary: In this study, the researchers examined the site and structural requirements for the dehydra-decyclization of cyclic ethers over ZrO2-based catalysts. They also investigated the activity of different types of ZrO2 for this reaction. The results provide insights for identifying the active sites on the ZrO2 surface.
Article
Chemistry, Physical
Alexander Wellmann, Lorenzo Grazia, Ricardo Bermejo-Deval, Maricruz Sanchez-Sanchez, Johannes A. Lercher
Summary: Promoters Cs+ and Sb4+ can affect the o-xylene oxidation pathways on TiO2 supported vanadium oxide catalysts. Sb4+ promotes the reaction by increasing the availability of oxygen for V site reoxidation at high temperatures, while Cs+ enhances V site reoxidation and increases the ratio of different types of oxygen on the surface.
JOURNAL OF CATALYSIS
(2022)
Article
Chemistry, Physical
Erfan Behravesh, Marko M. Melander, Johan Warna, Tapio Salmi, Karoliina Honkala, Dmitry Yu Murzin
Summary: The study combined experiments, DFT calculations, and kinetic modeling to elucidate the mechanism and kinetics of ethanol oxidative dehydrogenation to acetaldehyde on gold catalysts, indicating the key role of ethanol-mediated oxygen activation in the reaction.
JOURNAL OF CATALYSIS
(2021)
Article
Chemistry, Multidisciplinary
Tingting Lv, Guoyin Zhu, Shengyang Dong, Qingquan Kong, Yi Peng, Shu Jiang, Guangxun Zhang, Zilin Yang, Shengyang Yang, Xiaochen Dong, Huan Pang, Yizhou Zhang
Summary: In this study, metal ions were successfully inserted into the interlayer spacing of layered vanadium oxide nanobelts through confined synthesis, significantly improving the electrochemical performance of aqueous zinc-ion batteries.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Natthapong Pongpichayakul, Kanlayawat Wangkawong, Paralee Waenkaew, Li Fang, Burapat Inceesungvorn, Jaroon Jakmunee, Surin Saipanya
Summary: In this study, Pt-decorated cerium zirconium oxide-modified multiwalled carbon nanotubes (Pt/CeZrO4/MCNT) were prepared as alternative catalysts to improve the activity of the ethanol oxidation reaction (EOR) in direct ethanol fuel cells (DEFCs). The prepared catalysts showed excellent electrochemical performance and stability, making them promising materials for enhancing the anodic oxidation reaction in DEFCs.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Review
Chemistry, Multidisciplinary
Justin C. Bui, Chanyeon Kim, Alex J. King, Oyinkansola Romiluyi, Ahmet Kusoglu, Adam Z. Weber, Alexis T. Bell
Summary: The electrochemical reduction of carbon dioxide (CO2R) driven by renewable electricity offers a promising route for reusing CO2 and producing carbon-containing chemicals and fuels sustainably. Optimizing the catalyst microenvironment and selectivity, as well as controlling the electrolyte and operating conditions, are crucial for achieving economic viability and high product yields.
ACCOUNTS OF CHEMICAL RESEARCH
(2022)
Article
Chemistry, Physical
Enrique Iglesia, David Hibbitts
JOURNAL OF CATALYSIS
(2022)
Article
Chemistry, Physical
Samuel L. Leung, David Hibbitts, Monica Garcia-Dieguez, Enrique Iglesia
Summary: Experimental and theoretical evidence suggests that H-2-D-2 isotopic equilibration occurs through non-competitive adsorption mechanisms at catalytic temperatures, without requiring recombinative desorption steps.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Correction
Energy & Fuels
Chanyeon Kim, Justin C. Bui, Xiaoyan Luo, Jason K. Cooper, Ahmet Kusoglu, Adam Z. Weber, Alexis T. Bell
Article
Chemistry, Physical
Ari F. Fischer, Enrique Iglesia
Summary: Support effects in alkene and arene hydrogenations on metal catalysts attributed to hydrogen spillover are caused by the desorption and hydrogenation of Pt-bound intermediates at acid-base pairs on certain oxides. Toluene-H2 reactions on Pt nanoparticles dispersed on SiO2 occur on surfaces with diverse coverages and reactivity, leading to preferential occupation by less reactive isomers. These less reactive species can desorb as methylcyclohexadiene molecules, which diffuse to nearby oxide surfaces and react, increasing the abundance of more reactive intermediates at Pt surfaces.
JOURNAL OF CATALYSIS
(2023)
Article
Chemistry, Physical
Andrew Hwang, Jason Wu, Andrew Bean Getsoian, Enrique Iglesia
Summary: Reduction-oxidation cycles in oxides are widely used in various applications and require coupling reactions at the surfaces of oxide crystals. CeO2-ZrO2 solid solutions (CZO) were used to study the kinetic relevance of surface reactions and diffusion in O-atom addition and removal. The experiments showed that O-removal rates depend on reductant pressures, while O-addition rates are similar for different reactants and can be affected by the presence of Pt nanoparticles.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Multidisciplinary
Liang Qi, Sonali Das, Yanfei Zhang, Danna Nozik, Bruce C. Gates, Alexis T. Bell
Summary: Catalysts for ethene hydroformylation were prepared by grafting Rh into nests of -SiOZn-OH or -SiOCo-OH species in BEA zeolite. The Rh dispersion increased with increasing M/Rh ratio and had a positive effect on the turnover frequency for ethene hydroformylation. The Co-containing catalyst exhibited higher activity and selectivity than the Zn-containing catalyst.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Physical
Danna Nozik, Alexis T. Bell
Summary: Ethane and propane derived from shale gas are preferred feedstocks for the production of aromatics. Ga/H-MFI zeolite exhibits high activity and selectivity for light alkane dehydroaromatization, with Ga3+ sites playing a crucial role. The enhanced activity of Ga/H-MFI is attributed to cooperative effects between Ga3+ sites and Bronsted acid protons.
Article
Chemistry, Multidisciplinary
Brooke Soobrian, Alex J. King, Justin C. Bui, Adam Z. Weber, Alexis T. Bell, Frances A. Houle
Summary: Artificial photosynthesis is a promising method to produce commodity chemicals using abundant chemical feedstocks and renewable energy sources. However, affordable and effective hands-on activities for primary school students to demonstrate and teach artificial photosynthesis are lacking. Educating young students on this topic is crucial for developing a diverse next-generation energy workforce. This study confirms that an active learning-based lesson plan using cheap and accessible materials can effectively educate a broad range of young students on artificial photosynthesis, as demonstrated by the improved understanding of fifth grade students before and after the lesson plan.
JOURNAL OF CHEMICAL EDUCATION
(2023)
Article
Chemistry, Physical
Enrique Iglesia, Haefa Mansour
Summary: Kinetic and isotopic measurements, along with theoretical assessments, were used to determine the identity and relevance of elementary steps and bound species in H-2-O-2 reactions on Pt surfaces. The reactions involve two kinetically-relevant O2 dissociation routes, one forming two bound O atoms on Pt atom ensembles within H* adlayers, and the other involving reactions with a H*-H* pair to form weakly bound hydrogen peroxide (*HOOH*). The results provide insights into the reaction mechanisms and can help improve catalytic processes.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Multidisciplinary
Nicholas R. Jaegers, Enrique Iglesia
Summary: Ni-based solids are effective catalysts for alkene dimerization, and the nature of their active centers and the identity and relevance of bound species and elementary reactions have been explored. A study shows that Ni centers grafted onto ordered MCM-41 mesopores lead to stable monomers that act as Lewis acid-base pairs and stabilize C-C coupling transition states. Density functional theory (DFT) treatments confirm the involvement of these active centers and pathways, which were not previously considered. The DFT-derived activation barriers for ethene dimerization are consistent with experimental measurements.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Nanoscience & Nanotechnology
Alex J. King, Adam Z. Weber, Alexis T. Bell
Summary: A metal-insulator-semiconductor (MIS) structure is an attractive photoelectrode-catalyst architecture for promoting photoelectrochemical reactions, such as the formation of H2 by proton reduction. Understanding how the insulator layer determines the photovoltage and what properties lead to high photovoltages is critical to the development of MIS structures for solar-to-chemical energy conversion.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Physical
John Safipour, Adam Z. Weber, Alexis T. Bell
Summary: Reactive carbon capture (RCC) is a promising solution for carbon capture and utilization. A systematic study found that RCC in aqueous environments is less effective and does not directly reduce into carbamate. Instead, the presence of amine solution suppresses the rate of CO formation while increasing that of H2.
ACS ENERGY LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Chanyeon Kim, Alex J. King, Shaul Aloni, Francesca M. Toma, Adam Z. Weber, Alexis T. Bell
Summary: Photoelectrochemical carbon-dioxide reduction (PEC CO2R) is a promising method for producing chemicals and fuels using sunlight, water, and carbon dioxide. However, the focus has been mostly on producing C-1 products, while the production of C2+ products has been rarely demonstrated. In this study, a Cu/TiO2/p-Si photocathode/catalyst structure was investigated to understand the effects of semiconductor-insulator interactions and illumination direction on the performance and product distribution. Coating the Cu surface with a thin bilayer of Sustainion/Nafion significantly enhanced the current density and faradaic efficiency to ethylene.
ENERGY & ENVIRONMENTAL SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Annette Bohme, Justin C. Bui, Aidan Q. Fenwick, Rohit Bhide, Cassidy N. Feltenberger, Alexandra J. Welch, Alex J. King, Alexis T. Bell, Adam Z. Weber, Shane Ardo, Harry A. Atwater
Summary: We investigated how the micrometer-scale morphology of a CO2R gas diffusion electrode (GDE) affects the mass transport properties and local CO2R performance. Using fluorescence confocal laser scanning microscopy (CLSM), we created local pOH maps around a copper GDE and observed that pOH decreases in microtrenches compared to the electrode surface. Multiphysics simulations correlated well with experimental measurements and suggested that the decreased pOH inside microcavities leads to enhanced selectivity towards multicarbon products. This study highlights the importance of a GDE's micromorphology on CO2R performance.
ENERGY & ENVIRONMENTAL SCIENCE
(2023)
