Article
Engineering, Chemical
Bowen Xu, Xin Meng, Zhong Xin, Daoming Jin, Rui Zhao, Wenhua Dai, Fan Xu, Dandan Yang
Summary: Ni-based halloysite methanation catalysts with various Mo contents were prepared using halloysites as supports. The addition of Mo enhanced the interaction between Ni and halloysite, preventing Ni aggregation and improving the catalyst activity and life. Mo also increased the electron density around Ni and facilitated the CO dissociation, improving the reaction activity under low temperature. The catalyst with 6Mo10Ni/eHNTs showed the best activity, achieving 100% CO conversion and 99.7% CH4 yield at 350°C. The addition of Mo also enhanced the catalyst's resistance to sintering and carbon deposition. This study demonstrates the potential industrial application of halloysite-supported methanation catalysts.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2023)
Article
Chemistry, Physical
Huihong Zhu, Zhiwei Mao, Bin Luo, Tao Yang, Xiang Feng, Hao Jin, Chong Peng, Chaohe Yang, Jifeng Wang, Xiangchen Fang
Summary: This study investigates the impact of two different morphologies of Ni-Mo/Al2O3 catalysts on the stability of vacuum residue hydroprocessing, finding that the spherical catalyst exhibits superior performance with lighter carbonaceous deposits and smaller coke weight. The enhanced performance is attributed to a higher bed expansion rate and better mass transfer ability of the spherical catalyst.
GREEN ENERGY & ENVIRONMENT
(2021)
Article
Chemistry, Physical
Herve Toulhoat
Summary: This paper discusses the importance of catalytic hydrogenation in upgrading aromatics into fuels and petrochemical bases, as well as the rim-edge model, the exceptional hydrogenation activities of NiMoS supported on NiSx, and the effects of doping with elements such as phosphorous, boron, and fluorine.
JOURNAL OF CATALYSIS
(2021)
Article
Chemistry, Applied
Wenbin Huang, Qiang Wei, Yasong Zhou, Xiaodong Liu, Meifang Liu, Pengfei Zhang, Zhusong Xu, Zhiqing Yu, Xiaohan Wang, Haoran Liu
Summary: A series of Ni modified Y zeolites were successfully synthesized by in-situ synthesis method, and NiMo/AxNiY catalysts were prepared. The results showed that Ni modification can affect the physical-chemical properties of the zeolites and catalysts, leading to a decrease in specific surface areas but an increase in acid sites and particle uniformity. The incorporation of Ni into Y zeolites improved the acid sites and Mo dispersion, enhancing the adsorption and hydrogenation performances of the catalysts.
Article
Energy & Fuels
Neeraj Pal, Vikas Verma, Azeem Khan, Ankit Mishra, Mohit Anand, Chodimella Venkata Pramod, Saleem Akhtar Farooqui, Anil Kumar Sinha
Summary: The study demonstrates the effectiveness of a heterogeneous mesoporous Ni-Mo/gamma-Al2O3 catalyst in removing metals from non-edible raw jatropha oil (RJO) during hydrodemetalation (HDM). Lower temperatures favor HDM, while higher temperatures promote RJO conversion. The catalyst shows promising potential for improving catalyst aging and green diesel production.
Article
Chemistry, Physical
Szu-Hua Chen, Ya-Chun Tseng, Sheng-Chiang Yang, Shawn D. Lin
Summary: The study investigated the conversion of furfural using Ni/SiO2 catalysts under a hydrogen atmosphere. Catalyst pretreatment affects Ni particle size, which in turn affects selectivity. Ni/SiO2-CR exhibits high selectivity to furfuryl alcohol (FA), while Ni/SiO2-R shows high selectivity to furan.
APPLIED CATALYSIS A-GENERAL
(2021)
Article
Chemistry, Multidisciplinary
Bin Wang, Qian Dong, Si-Yao Wang, Pei-Ya Li, Shi-Yuan Wang, Shu-Han Lu, Tao Fang
Summary: This study synthesized a Ni-Mo alloy catalyst supported by commercial activated carbon and optimized its ratio and preparation conditions. The results showed that Mo doping significantly promoted the hydrogenation reaction of N-ethylcarbazole. The catalyst achieved high hydrogenation rate in a short time and effectively improved the selectivity of fully hydrogenated products.
FRONTIERS IN CHEMISTRY
(2022)
Article
Chemistry, Physical
Christian Frederik Weise, Hanne Falsig, Poul Georg Moses, Stig Helveg, Michael Brorson, Lars Pilsgaard Hansen
Summary: The Pt-Co-Mo-S catalyst contains mainly single-layer MoS2 nanocrystals with Co atoms fully covering the S-edge terminations, and Pt atoms uniquely attached to corner and edge sites in a platinum(IV) sulfide-like structural motif. Platinum is suggested to reduce the sulfur binding energy and increase the abundance of coordinately undersaturated sites (CUS) without necessarily changing the reactivity towards 4,6-DMDBT molecules, although further studies are needed for a detailed understanding.
JOURNAL OF CATALYSIS
(2021)
Article
Chemistry, Multidisciplinary
Chuangchuang Yang, Anpeng Hu, Qiaoling Dai, Qinghe Yang, Ranran Hou, Zhiwei Liu
Summary: This study investigates the structure and catalytic performance of Ni-MoS2 catalysts for hydrodesulfurization (HDS) using hydrothermal treatment and calcination processes. The effects of hydrothermal treatment temperature and calcination temperature on catalyst structures were analyzed using various characterization techniques. The results showed that an appropriate hydrothermal treatment temperature could lead to catalysts with desirable desulfurization activity.
Article
Chemistry, Physical
Patricia Perez-Romo, Candido Aguilar-Barrera, Georgina C. Laredo, Carlos Angeles-Chavez, Jose Fripiat
Summary: Silica poisoning during hydrotreating can severely deactivate catalysts, but in this study, selective removal of silica using glycerol depolymerization process restored the catalytic activity and physical properties successfully. The catalyst samples were analyzed using various techniques before and after silica compound removal.
APPLIED CATALYSIS A-GENERAL
(2021)
Article
Chemistry, Multidisciplinary
Yang Li, Shouwei Zuo, Qiao-Hong Li, Xin Wu, Jing Zhang, Huabin Zhang, Jian Zhang
Summary: The study successfully achieved uniform vacancy manufacturing and three-dimensional self-assembly of MoS2 nanosheets using a self-engaged strategy, leading to improved hydrogen evolution activity and stability.
Article
Physics, Applied
Gernot Pacholik, Ludwig Enzlberger, Anna Benzer, Raffael Rameshan, Markus Latschka, Christoph Rameshan, Karin Foettinger
Summary: In this study, various Co, Ni, and K modified MoS2-based catalysts were synthesized and compared in their catalytic performance in CO2 hydrogenation, revealing that the addition of K reduced the selectivity to CH4 and affected the temperature at which the maximum methanol formation rate occurred. The materials were characterized using multiple techniques, and different species of Mo and O were observed under reaction conditions.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2021)
Article
Chemistry, Physical
Siyi Jiang, Yujing Weng, Yangbin Ren, Shihang Meng, Xiaoman Li, Chao Huang, Yulong Zhang, Qi Sun
Summary: Selective catalytic conversion of carbon dioxide to methanol is achieved by using a bifunctional molybdenum disulfide catalyst with magnesium oxide, nickel, and potassium promoters. The addition of the potassium promoter improves methanol selectivity, providing a new strategy for improved product selectivity and space-time yield of methanol in CO2 hydrogenation.
Article
Biochemistry & Molecular Biology
Yongning Yuan, Liyue Qi, Zhuxian Gao, Tuo Guo, Dongdong Zhai, Yurong He, Jingjing Ma, Qingjie Guo
Summary: Preparation of methanol chemicals from CO2 and H-2 gas is a positive step towards achieving carbon neutrality. However, developing catalysts with high selectivity is challenging due to the side reaction of RWGS and low-temperature characteristics of CO2 hydrogenation. Doping MoS2 with Ni and Co can prevent contact between CO2 and H-2 and enhance the selectivity of the main product, CH3OH. This strategy of metal doping has reference significance for future catalyst research and development.
Article
Chemistry, Applied
Kai Wu, Yushuai Sang, Saravanan Kasipandi, Yiming Ma, Hairui Jiao, Qingfeng Liu, Hong Chen, Yongdan Li
Summary: In this study, depolymerization of enzymatic hydrolysis lignin (EHL) was carried out using one-step hydrothermal-synthesized MoS2 in ethanol without hydrogen gas. Value-added aromatic molecules, mainly alkyl-substituted phenols (A-Ps), were obtained without the formation of char or tar. The highest aromatic monomer yield of 226.4 mg/g EHL was achieved over the MoS2 prepared with thioacetamide and sodium molybdate as precursors (STA-MoS2) at 320 degrees C for 12 h. Proper ratios of Mo6+/Mo5+ and (Mo6++Mo5+)/Mo4+ on the surface of MoS2 catalysts were found to be significant for attaining high overall aromatic monomer yield. MoOxSy species with Mo5+ and S22- was proposed as the active site for the production of complex alkyl phenols via demethoxylation and alkylation. Carbon deposition and exchanges of sulfur and oxygen atoms resulting from oxidation are likely responsible for catalyst deactivation.
Article
Chemistry, Physical
Linxiao Chen, Laura C. Meyer, Libor Kovarik, Debora Meira, Xavier Pereira-Hernandez, Honghong Shi, Konstantin Khivantsev, Oliver Y. Gutierrez, Janos Szanyi
Summary: This study discovers that low-loading Ru/CeO2 exhibits remarkable catalytic performance in the hydrogenolysis of polyolefin plastics, with high conversion efficiency, low selectivity toward CH4, and good isomerization ability. The catalytic behavior changes coincide with the transition from well-defined to highly disordered Ru species in the low-loading range.
Article
Energy & Fuels
Cheng Zhu, Oliver Y. Gutierrez, Daniel M. Santosa, Igor Kutnyakov, Roland Weindl, Hui Shi, Huamin Wang
Summary: The coprocessing of biocrudes with petroleum streams has potential for renewable fuel production, but can cause catalyst deactivation. This study investigated the deactivation modes of a hydrotreating catalyst used for coprocessing biocrude with diesel. It was found that catalyst deactivation was mainly attributed to fouling by carbonaceous species and metal contaminants from biocrudes.
Article
Chemistry, Multidisciplinary
Lingli Ni, Rachit Khare, Ricardo Bermejo-Deval, Ruixue Zhao, Lei Tao, Yue Liu, Johannes A. Lercher
Summary: A highly selective Ga-modified zeolite BEA has been successfully synthesized for propane dehydrogenation. The propane dehydrogenation rate is determined by different factors under different conditions. The active sites are identified as dehydrated and tetrahedrally coordinated Ga3+, and the selectivity towards aromatics is low.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Qiang Liu, Niklas Pfriem, Guanhua Cheng, Eszter Barath, Yue Liu, Johannes A. Lercher
Summary: The ionic environment inside microporous zeolites can significantly affect the catalytic turnover rates by modifying the chemical potential of the reactants and transition states. However, zeolites with high ionic strength seem to have a limit to the rate enhancement for the aqueous-phase dehydration of alcohols. This limitation is hypothesized to be caused by spatial constraints in the pores, such as size exclusion effects. This study demonstrates that the increase in turnover rate, the formation of a maximum, and the subsequent rate drop are intrinsic consequences of the increasingly dense ionic environment in zeolite.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Jian Zheng, Laura Loebbert, Saumil Chheda, Navneet Khetrapal, Julian Schmid, Carlo Alberto Gaggioli, Benjamin Yeh, Ricardo Bermejo-Deval, Radha Kishan Motkuri, Mahalingam Balasubramanian, John L. Fulton, Oliver Y. Gutierrez, J. Ilja Siepmann, Matthew Neurock, Laura Gagliardi, Johannes A. Lercher
Summary: Homotopic sites are ideal for mechanistic studies and optimal control of catalytic transformations. Nickel cations in different environments show different selectivity in the reaction of 1-butene, and the reaction mechanism follows the Cossee-Arlman mechanism.
JOURNAL OF CATALYSIS
(2022)
Article
Chemistry, Multidisciplinary
Laura Loebbert, Saumil Chheda, Jian Zheng, Navneet Khetrapal, Julian Schmid, Ruixue Zhao, Carlo A. Gaggioli, Donald M. Camaioni, Ricardo Bermejo-Deval, Oliver Y. Gutierrez, Yue Liu, J. Ilja Siepmann, Matthew Neurock, Laura Gagliardi, Johannes A. Lercher
Summary: Grafting metal cations to missing linker defect sites in zirconium-based metal-organic frameworks can produce well-defined and homotopic catalytically active sites. This study focuses on the synthesis and characterization of a group of metal catalysts supported by UiO-66, which showed varying catalytic activities for alkene dimerization. The removal of molecular water from the active site significantly increased the catalytic activity for 1-butene dimerization, and density functional theory calculations provided a molecular level understanding of the differences in activity among different metal catalysts.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Physical
Ruixue Zhao, Rachit Khare, Yang Zhang, Maricruz Sanchez-Sanchez, Ricardo Bermejo-Deval, Yue Liu, Johannes A. Lercher
Summary: Steric confinement in zeolites affects the catalytic conversion of alkanes. Silica species grafted near Bronsted acid sites in H-ZSM-5 zeolite enhance the binding of bases and increase the reaction rate of protolytic cracking of n-pentane with a lower activation energy. The presence of extra-framework silica leads to an earlier transition state and better stabilization of carbonium ions compared to extra-framework alumina.
Article
Multidisciplinary Sciences
Wei Zhang, Sungmin Kim, Lennart Wahl, Rachit Khare, Lillian Hale, Jianzhi Hu, Donald M. Camaioni, Oliver Y. Gutierrez, Yue Liu, Johannes A. Lercher
Summary: We propose a unique approach to selectively upcycle polyolefin waste by utilizing a highly ionic reaction environment, which increases polymer reactivity and reduces energy required for breaking carbon-carbon bonds. By catalyzing endothermic cleavage and exothermic alkylation reactions, we are able to convert polyethylene and polypropylene to liquid isoalkanes at temperatures below 100 degrees C. This process offers a high yield conversion of unprocessed postconsumer items into high-quality liquid alkanes.
Article
Chemistry, Physical
Yong Wang, Xiaofeng Chen, Hui Shi, Johannes A. Lercher
Summary: Metal oxides of group 4-6 elements are found to be active and stable catalysts for H2S reforming of methane, with dynamical binding of sulfur species (S*) to metal cations as the key active sites. Analysis of kinetic data and isotopic substitution effects reveals that S*-mediated C-H bond cleavage is the most plausible rate-limiting step common for all catalysts, with subtle yet essential differences in the thermodynamic stability of S* between 3d and 4d/5d catalysts.
Article
Chemistry, Applied
Feng Chen, Sungmin Kim, Dushyant Barpaga, John. L. L. Fulton, Radha Kishan Motkuri, Oliver. Y. Y. Gutierrez, Donald. M. M. Camaioni, Johannes. A. A. Lercher
Summary: Bronsted-acid sites are introduced on the ZrO2 nodes of UiO-66 MOFs via -OSO3H groups. These sites exhibit strong Bronsted acidity and are active for cyclohexanol and ethanol dehydration reactions in different phases. The activity of Bronsted acid sites at nodes is improved by increasing sulfur concentration, which leads to the formation of two interacting groups [(&mu(3)-OSO3H)(2)] through hydrogen bonding. The catalytic activity can be manipulated by functionalizing zirconia nodes of the MOF framework.
TOPICS IN CATALYSIS
(2023)
Article
Chemistry, Physical
Benjamin Yeh, Saumil Chheda, Jian Zheng, Julian Schmid, Laura Loebbert, Ricardo Bermejo-Deval, Oliver Y. Gutierrez, Johannes A. Lercher, Laura Gagliardi, Aditya Bhan
Summary: In this study, the steady state propylene oligomerization rates and selectivities were measured on Ni/UiO-66 metal organic framework (MOF), demonstrating the validity of the Cossee-Arlman mechanism. It was found that propylene dimerization reaction follows a first-order kinetics with respect to propylene pressure, and the selectivities are consistent with the selectivity expressions derived from the Cossee-Arlman mechanism.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Oliver Y. Gutierrez, Katarzyna Grubel, Jotheeswari Kothandaraman, Juan A. Lopez-Ruiz, Kriston P. Brooks, Mark E. Bowden, Tom Autrey
Summary: Using hydrogen to store energy is crucial for achieving sustainability and addressing climate change. Liquid hydrogen carriers can overcome the challenges of handling molecular hydrogen. The bicarbonate-formate cycle, utilizing formate ions as hydrogen and energy carriers, offers a promising solution. This system combines electrochemical and thermochemical operations and has the potential for CO2 capture and energy storage.