Article
Chemistry, Physical
Chenggen Li, Qingyang Zhang, Zhenggang Xu, Li Liu, Ting Zhu, Zhiwen Chen, Yuan Dong, Ming Yang
Summary: In this work, a highly dispersed CeO2 nanoparticle-modified Pd/Al2O3 catalyst was prepared and applied for the reversible hydrogenation and dehydrogenation of N-propylcarbazole. The catalyst Pd/CeAl-20 exhibited better catalytic performance compared to the commercially available 1 wt% Pd/Al2O3 catalyst, achieving complete hydrogenation and dehydrogenation within 180 minutes. This study reveals the crucial role of combined promotion of the active site size and chemical microenvironment for N-heterocycle hydrogenation and dehydrogenation.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Engineering, Environmental
Guanfeng Tian, Youqing Wu, Shiyong Wu, Sheng Huang, Jinsheng Gao
Summary: The Pd/MnO/In2O3 catalyst prepared by an in-situ reduction method showed high catalytic activity for CO2 hydrogenation to methanol, with the methanol space-time yield of 1 wt% Pd/MnO/In2O3 being 4.8 times higher than that of MnO/In2O3. The catalyst also maintained a methanol selectivity above 70% at temperatures below 280°C. The in-situ reduction method proved to be an effective route for preparing Pd/MnO/In2O3 catalyst for CO2 hydrogenation to methanol.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2022)
Article
Chemistry, Physical
Kyungho Lee, Uzma Anjum, Cecilia Mondelli, Qian He, Shinya Furukawa, Javier Perez-Ramirez, Sergey M. Kozlov, Ning Yan, Thaylan Pinheiro Arajo
Summary: In this study, an atomic Pd-promoted ZnZrOx solid solution catalyst (Pd-ZnZrOx) was designed and synthesized, showing excellent activity and stability in the conversion of CO2 to methanol.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2022)
Article
Chemistry, Physical
Phathutshedzo R. Khangale, Reinout Meijboom, Kalala Jalama
Summary: In this study, the deactivation rate of 15%Co-6%K/Al2O3 Fischer-Tropsch catalyst during the hydrogenation of CO2 to longer-chained hydrocarbons was investigated. The presence of CO2 in the feed negatively impacted catalyst stability and the production of longer-chain hydrocarbons, mainly leading to an increase in methane formation and a decrease in C5+ selectivity. This was observed to be partly due to the formation of cobalt carbide on the catalyst surface, which contributed to decreased CO2 conversion rates and C5+ selectivity.
Article
Chemistry, Applied
Hangjie Li, Liang Wang, Feng-Shou Xiao
Summary: By introducing silica promoter, the Cu/ZnO/Al2O3 catalyst has achieved significantly improved methanol selectivity and catalyst durability.
Article
Chemistry, Physical
Yuanqing Liu, Michael Wu, Garry L. Rempel, Flora T. T. Ng
Summary: The catalytic process of glycerol hydrogenolysis to produce 1,2-propandiol without external hydrogen addition can be improved by utilizing in situ hydrogen from methanol steam reforming. The addition of Pd to a Cu/MgO/Al2O3 catalyst enhances glycerol conversion and 1,2-PD selectivity. Adjusting glycerol feed concentration and incorporating Pd are essential for achieving high selectivity of 1,2-PD and glycerol conversion in the reaction.
Article
Energy & Fuels
Luqman Abdullahi Sani, Chao Wang, Mengjuan Zhang, Haolong Bai, Ping An, Zhennan Han, Lei Shi, Kangjun Wang, Dingrong Bai, Guangwen Xu, Fabing Su, Zhanguo Zhang
Summary: Introducing Yb modification in the preparation of Ni/Al2O3 catalysts promotes the dispersion of reducible NiO on Al2O3 and leads to the creation of new Yb-involved CO2 chemisorption sites. The Yb-modified Ni/Al2O3 catalysts exhibit higher catalytic activities and stability than the Ni/Al2O3 catalysts without Yb.
Article
Chemistry, Physical
Shuai Chen, Tianxing Yang, Hao Lu, Yanan Liu, Yufei He, Qiang Li, Junxian Gao, Junting Feng, Hong Yan, Jeffrey T. Miller, Dianqing Li
Summary: In this study, atomically dispersed La was introduced into Al2O3 through a simple bottom-up synthesis, followed by the addition of Pd to prepare microspherical Pd/La-Al2O3 catalyst with potential for hydrogenation applications. The Pd/La-Al2O3 catalyst exhibited enhanced activity for various hydrogenation reactions and functional groups, and the incorporation of isolated O(-La) sites adjacent to the Pd nanoparticles provided a feasible strategy for designing high-efficiency hydrogenation catalysts and had important implications for the development of the commercial hydrogenation process.
Article
Chemistry, Applied
Kuen-Song Lin, Cheng-Yan Tang, Ndumiso Vukile Mdlovu, Chi-Jung Chang, Chao-Lung Chiang, Zhi-Min Cai
Summary: Ni/Al2O3 prepared by impregnation can be used for CO2 hydrogenation into carbon nano fibers with high catalytic performance. The unique microstructure and high specific surface area of the prepared Ni/Al2O3 contribute to its enhanced catalytic activity. The configuration of CNFs was characterized by its unique ID/IG ratio in the Raman spectrum and observed morphologically by FE-SEM and HR-TEM.
Article
Chemistry, Multidisciplinary
Kazumasa Murata, Takumi Shiotani, Junya Ohyama, Atsushi Satsuma
Summary: There is a positive correlation between the C=C selective hydrogenation activity of cinnamaldehyde (CAL) and the fraction of the Pd step site on Pd nanoparticles. Due to a high fraction of step sites, Pd/theta-Al2O3 catalysts with Pd particle size of 5-10 nm exhibit high activity for the C=C selective hydrogenation of CAL.
Article
Engineering, Chemical
Shengyan Meng, Liang Wu, Miao Liu, Zhaolun Cui, Qian Chen, Shangkun Li, Jiahui Yan, Li Wang, Xinkui Wang, Ji Qian, Hongchen Guo, Jinhai Niu, Annemie Bogaerts, Yanhui Yi
Summary: A plasma-assisted CO2 hydrogenation to CH3OH was conducted over Fe2O3/α-Al2O3 catalysts, achieving 12% CO2 conversion and 58% CH3OH selectivity. The effect of various supports and loadings of Fe-based catalysts, as well as optimized reaction conditions, were investigated. The study reveals the role of chemisorbed oxygen species as a key intermediate in the reaction.
Article
Chemistry, Physical
Sang Jae Park, Xiang Wang, Madelyn R. Ball, Laura Proano, Zili Wu, Christopher W. Jones
Summary: Catalytic CO2 sorbents play a crucial role in CO2 capture and utilization. This study investigates the performance differences between a CO2 methanation catalyst and a catalytic sorbent, showing that the latter may have an additional kinetically relevant irreversible step in the CO2 conversion process.
CATALYSIS SCIENCE & TECHNOLOGY
(2022)
Article
Chemistry, Applied
Liya Dai, Yao Chen, Renjie Liu, Xin Li, Niamat Ullah, Zhenhua Li
Summary: A series of K-promoted Fe/CNT catalysts were prepared and it was found that the catalyst with a K/Fe mole ratio of 0.3 showed the best performance, with higher CO2 conversion rate and C5+ selectivity. The K-modified catalysts exhibited higher specific surface area and stronger CO2 chemisorption, which improved catalytic activity.
APPLIED ORGANOMETALLIC CHEMISTRY
(2021)
Article
Multidisciplinary Sciences
Bin Shao, Zhi-Qiang Wang, Xue-Qing Gong, Honglai Liu, Feng Qian, P. Hu, Jun Hu
Summary: The integrated CO2 capture and conversion (iCCC) technology is a promising cost-effective approach for Carbon Neutrality. The lack of molecular consensus about the synergistic effect between adsorption and in-situ catalytic reaction hampers its development. In this study, the synergies between CO2 capture and in-situ conversion are illustrated through high-temperature Calcium-looping and dry reforming of methane processes.
NATURE COMMUNICATIONS
(2023)
Article
Engineering, Chemical
Deng Pan, Yanan Wang, Han Li, Yuzhe Zhang, Qian Liang, Man Zhou, Zhongyu Li, Song Xu
Summary: The catalyst Co/CeO2 prepared by Ce-MOF and ZIF-67 precursor demonstrates efficient photothermal CO2 methanation, with high methane and carbon monoxide yields, as well as selectivity and catalytic durability.
SEPARATION AND PURIFICATION TECHNOLOGY
(2024)
Article
Chemistry, Physical
Junya Ohyama, Daiki Abe, Airi Hirayama, Hiroki Iwai, Yuka Tsuchimura, Kazuki Sakamoto, Momoka Irikura, Yuri Nakamura, Hiroshi Yoshida, Masato Machida, Shun Nishimura, Tomokazu Yamamoto, Syo Matsumura, Keisuke Takahashi
Summary: The catalytic oxidation of methane to formaldehyde and methanol is a promising process due to its energy efficiency advantage. However, selectively obtaining partial oxidation products in the direct oxidation of methane is challenging. In this study, Co/SiO2 materials with different Co loadings were used and it was found that low loading of Co (<0.1 wt%) showed high selectivity for partial oxidation, mainly producing formaldehyde, while high Co loadings promoted complete oxidation. Structural analysis suggested that single Co atoms at low loadings were effective in selective oxidation, while Co3O4 nanoparticles at high loadings promoted complete oxidation.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Physical
Junya Ohyama, Yuka Tsuchimura, Airi Hirayama, Hiroki Iwai, Hiroshi Yoshida, Masato Machida, Shun Nishimura, Kazuo Kato, Keisuke Takahashi
Summary: The catalytic performance of Cu zeolites for the direct conversion of methane to methanol was investigated. The reduction rate of Cu-CHA was found to be highly correlated with catalytic activity. The reduction of Cu2+ is associated with the activation of C-H bonds in CH4, which is the rate-determining step for the reaction. The local structure of Cu-CHA affects selectivity, turnover frequency, and Cu2+ reduction rate.
Article
Chemistry, Physical
Masato Machida, Shundai Iwashita, Tetsuya Sato, Hiroshi Yoshida, Junya Ohyama, Masao Yoshioka, Shiro Miwa, Takeshi Hashishin
Summary: This study found that Rh catalysts supported on Al2O3-based oxides lose their catalytic activity when exposed to high-temperature oxidizing environments. The diffusion of Rh3+ ions into the support structure causes substantial thermal deactivation. However, the layered structure of LaMgAl11O19 hinders the diffusion of Rh3+, preserving the catalytic activity.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Physical
Ayumi Fujiwara, Yutaro Tsurunari, Shundai Iwashita, Hiroshi Yoshida, Junya Ohyama, Masato Machida
Summary: In three-way catalytic converters, perturbations in exhaust gas composition between fuel-rich and fuel-lean conditions affect catalyst surface and conversion efficiencies. In this study, real-time changes in surface states of Pd-based catalysts were monitored using in situ diffuse reflectance spectroscopy. The oxidation state of Pd fluctuated in sync with the perturbations, with smaller oscillation amplitude on CeO2-ZrO2 (CZ) compared to Al2O3. CZ's oxygen scavenging function buffered oxidative degradation, resulting in higher reaction rates and preventing coke deposition. This study highlights the usefulness of in situ DRS in understanding transient catalytic processes and bridging the gap between on-board performances and laboratory tests.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Physical
Junya Ohyama, Yuka Tsuchimura, Hiroshi Yoshida, Masato Machida, Shun Nishimura, Keisuke Takahashi
Summary: The catalytic performance of Cu-CHA catalysts for partial CH4 oxidation was improved through refinement of catalyst composition using the Bayesian optimization method. Experimental validation showed that optimization of Cu-ion exchange rates (Cu IERs) and Si/Al2 ratios was achieved in only two cycles of the Bayesian optimization process.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Energy & Fuels
Yuka Tsuchimura, Hiroshi Yoshida, Masato Machida, Shun Nishimura, Keisuke Takahashi, Junya Ohyama
Summary: Cu-CHA exhibits high catalytic performance in the direct oxidation of CH4 to CH3OH. The catalytic activity varies with the composition of Cu-CHA. Three groups of Cu species were identified based on their catalytic performance: low Cu/Al ratio for high selectivity and low activity, medium Cu/Al ratio for high selectivity and high activity in CH3OH production, and high Cu/Al ratio for high activity in complete oxidation of CH4 to CO2. The mono-(mu-oxo) di-Cu species in Cu-CHA is proposed as the active species for the catalytic reaction.
Article
Engineering, Chemical
Shundai Iwashita, Ayumi Fujiwara, Hiroshi Yoshida, Junya Ohyama, Takeshi Miki, Masato Machida
Summary: The thermal deactivation mechanism of Pd/CeO2-ZrO2-Al2O3 three-way catalysts (TWCs) was investigated through engine-bench aging and driving tests. The results showed that high temperature and prolonged aging promoted the growth of Pd particles, leading to a decrease in catalytic activity. A sintering kinetic model was developed to predict TWC deactivation and lifetime based on the analysis of particle growth kinetics.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2023)
Article
Chemistry, Physical
Masato Machida, Hideto Yoshida, Naoto Kamiuchi, Yasuhiro Fujino, Takeshi Miki, Masaaki Haneda, Yutaro Tsurunari, Shundai Iwashita, Rion Ohta, Hiroshi Yoshida, Junya Ohyama, Masayuki Tsushida
Summary: Under dynamic SLR cycle conditions, the Rh/ZrO2-CeO2 (Rh/ZC) three-way catalyst experienced more severe deactivation compared to static conditions. The complete encapsulation of Rh particles with a ZC overlayer under dynamic SLR cycle conditions led to physical blockage and suppressed catalytic activity. This encapsulation phenomenon was not recovered by post-treatment in air at 1000 degrees C.
Article
Chemistry, Physical
Junya Ohyama, Hideto Ushijima, Takashi Yamashita, Akihiro Yamashita, Hiroshi Yoshida, Masato Machida
Summary: Improving the catalysts for hydrogen oxidation reaction (HOR) in alkaline conditions is crucial for the development of anion exchange membrane fuel cells. Previous studies have shown that Pt catalysts can be enhanced by forming coordinationally saturated surface sites and also by combining Pt with other metals. This study demonstrates the use of Pt-Ni alloy thin films as highly active structures in alkaline HOR, with improved activity compared to Pt monometal thin-film and nanoparticle catalysts.
ACS APPLIED ENERGY MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Masato Machida, Hideto Yoshida, Naoto Kamiuchi, Yasuhiro Fujino, Takeshi Miki, Masaaki Haneda, Yutaro Tsurunari, Shundai Iwashita, Rion Ohta, Hiroshi Yoshida, Junya Ohyama
Summary: This study investigates the performance of catalysts after real engine aging and finds that pre-aged catalysts can maintain better catalytic performance at high temperatures. It is found that the migration of Rh nanoparticles from the ZC surface to the Al2O3 binder interface plays a crucial role in mitigating the encapsulation of Rh nanoparticles by ZC. By using a dual-oxide support formulation, the deterioration extent of the catalyst and the oxygen storage capacity performance can be effectively improved.
ACS APPLIED NANO MATERIALS
(2023)
Review
Chemistry, Physical
Hiroshi Yoshida, Masato Machida
Summary: Although most solid catalysts have a three-dimensional structure of nanoparticles dispersed on a porous support, this structure is not optimal for all catalytic reactions. This article introduces a unique catalytic performance of a two-dimensional metal foil-supported nanometric Rh thin film, which is particularly suitable for CO-NO reaction and three-way catalytic reaction.
Article
Chemistry, Physical
Masato Machida, Hideto Yoshida, Naoto Kamiuchi, Yasuhiro Fujino, Takeshi Miki, Masaaki Haneda, Yutaro Tsurunari, Shundai Iwashita, Rion Ohta, Hiroshi Yoshida, Junya Ohyama, Masayuki Tsushida
Summary: A Rh/ZrO2-CeO2 (Rh/ZC) three-way catalyst exhibited more severe deactivation under dynamic SLR cycle conditions compared to static conditions. The total encapsulation of Rh particles by a ZC overlayer led to physical blockage and suppressed catalytic activity. The encapsulation under a dynamic SLR cycle condition suggests the activation of ZC migration near the metal-support interface.
Article
Chemistry, Physical
Hiroki Iwai, Fumiya Nishino, Tomokazu Yamamoto, Masaki Kudo, Masayuki Tsushida, Hiroshi Yoshida, Masato Machida, Junya Ohyama
Summary: Researchers have successfully predicted and removed the background image of supported metal nanoparticles using a deep learning-based image inpainting method. The 3D reconstruction of the extracted images reveals the atomic structure and deformed shape of the nanoparticles, providing insights into their catalytic activity. This study demonstrates the importance of 3D atomic-scale analysis in understanding and designing supported metal catalysts.
Article
Chemistry, Physical
Masato Machida, Shundai Iwashita, Tetsuya Sato, Hiroshi Yoshida, Junya Ohyama, Masao Yoshioka, Shiro Miwa, Takeshi Hashishin
Summary: When Rh catalysts supported on Al2O3-based oxides are exposed to a high-temperature oxidizing environment, they lose their three-way catalytic activity due to the diffusion of Rh3+ into the support structure. The diffusion of Rh3+ is suppressed in the layered structure of hexaaluminate, which effectively blocks further penetration and preserves their reduction to active metallic Rh nanoparticles.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Materials Science, Ceramics
Alam S. M. Nur, Asuka Ikematsu, Hiroshi Yoshida, Masato Machida
Summary: Molten-state potassium metavanadate supported on mesoporous SiO2 materials is an active catalyst for SO3 decomposition, and the addition of phosphate can enhance its catalytic activity and form mixed phosphate vanadate KV2PO8.
JOURNAL OF THE CERAMIC SOCIETY OF JAPAN
(2022)
Article
Chemistry, Multidisciplinary
Xuemei Liu, Chaonan Cui, Shuoshuo Wei, Jinyu Han, Xinli Zhu, Qingfeng Ge, Hua Wang
Summary: This study presents a new strategy for designing efficient photocatalysts that can convert CO2 into hydrocarbons by utilizing synergistic catalytic sites. The findings provide a solution for the selective photocatalytic reduction of CO2 to CH4.
Article
Chemistry, Multidisciplinary
Chengxian Hu, Dan Wang, Lu Wang, Ying Fu, Zhengyin Du
Summary: A novel one-pot, three-component reaction conducted under electrochemical conditions was studied. The reaction involved 2-aminothiophenols, aldehydes, and malononitrile, using TBABF4 as an electrolyte and CuI as a catalyst. The proposed reaction mechanism suggested that CuI served as an electron relay. This method offers simplified operation, high atom economy, and mild reaction conditions.
Article
Chemistry, Multidisciplinary
Zhi Yang, Yu Chen, Linxi Wan, Yuxiao Li, Dan Chen, Jianlin Tao, Pei Tang, Fen-Er Chen
Summary: A highly enantioselective method for the complete hydrogenation of pyrimidinium salts using Ir/(S,S)-f-Binaphane complex as the catalyst was developed. This method provides easy access to fully saturated chiral hexahydropyrimidines, which are prevalent in many bioactive molecules. The reactions exhibit high yields and enantioselectivities under mild reaction conditions without additives. Successful application of this methodology in a continuous flow fashion further extends its practical utility.
Article
Chemistry, Multidisciplinary
Tina Jeoh, Jennifer Danger Nill, Wujun Zhao, Sankar Raju Narayanasamy, Liang Chen, Hoi-Ying N. Holman
Summary: In this study, the enzymatic hydrolysis of cellulose was investigated using real-time infrared spectromicroscopy. The spatial heterogeneity of cellulose was found to impact the hydrolysis kinetics. Hydration affected cellulose ordering, and Cel7A preferentially removed less extensively hydrogen bonded cellulose.
Article
Chemistry, Multidisciplinary
Tiphaine Richard, Walid Abdallah, Xavier Trivelli, Mathieu Sauthier, Clement Dumont
Summary: An effective method of grafting functionalities onto lignin based on glycerol carbonate has been developed using an efficient nickel-catalysed telomerisation reaction. This method allows lignin to have new reactive functions and reduces the glass transition temperatures of modified lignins, thereby expanding the application range of lignin-based resins.
Article
Chemistry, Multidisciplinary
Jing Qi, Xiyan Wang, Gan Wang, Srinivas Reddy Dubbaka, Patrick ONeill, Hwee Ting Ang, Jie Wu
Summary: This study presents a green and environmentally friendly approach for the synthesis of imides using electrocatalytic oxidation with H2O as the oxygen source. The method eliminates the need for toxic or expensive oxidants and achieves high yields under mild reaction conditions. It shows broad substrate compatibility and potential for industrial applications.
Article
Chemistry, Multidisciplinary
Babasaheb Sopan Gore, Lin-Wei Pan, Jun-Hao Lin, Yi-Chi Luo, Jeh-Jeng Wang
Summary: Here, we report a visible light-promoted intramolecular radical cascade reaction for the construction of fluorenol and naphthalene-fused cyclopropyl carbaldehyde derivatives. This method offers mild reaction conditions, a broad substrate scope, excellent step efficiency, and scalability, without the need for external chemical oxidants. The novelty of this protocol was demonstrated by synthesizing chrysene analogs and performing late-stage functionalizations.
Article
Chemistry, Multidisciplinary
Juho Antti Sirvio, Idamaria Romakkaniemi, Juha Ahola, Svitlana Filonenko, Juha P. Heiskanen, Ari Ammala
Summary: This article discusses the method of using supramolecular interaction between an aromatic hydrogen bond donor and lignin to achieve rapid delignification of softwood at low temperatures.
Article
Chemistry, Multidisciplinary
Yunyan Meng, Chunxiang Pan, Na Liu, Hongjiang Li, Zixiu Liu, Yao Deng, Zixiang Wei, Jianbin Xu, Baomin Fan
Summary: A novel visible light-driven synthesis method for 2,3-diamines has been developed, which has mild conditions, avoids the use of metal reagents, and can synthesize diamines and diols in one pot.
Article
Chemistry, Multidisciplinary
Mingqing Huang, Haiyang Huang, Mengyao You, Xinxin Zhang, Longgen Sun, Chao Chen, Zhichao Mei, Ruchun Yang, Qiang Xiao
Summary: A direct air-oxidized strategy for the synthesis of benzo[b]phosphole oxides was developed in this study. Arylphosphine oxides were transformed into phosphinoyl radicals, which were further combined with various alkynes to achieve the desired products. DFT calculations revealed the mechanism of phosphinoyl radical formation.
Article
Chemistry, Multidisciplinary
Anwei Wang, Jiayin Huang, Chunsheng Zhao, Yu Fan, Junfeng Qian, Qun Chen, Mingyang He, Weiyou Zhou
Summary: This study demonstrates an innovative strategy for the aerobic oxidation of C(sp(3))-H bonds using gamma-valerolactone. By optimizing the reaction conditions and utilizing specific catalysts, efficient oxidation of C(sp(3))-H bonds is achieved with good chemoselectivity in certain cases.
Article
Chemistry, Multidisciplinary
Shun Li, Likai Tong, Zhijian Peng, Bo Zhang, Xiuli Fu
Summary: Sulfide compounds show promise as electrocatalysts for water splitting, but their performance is limited by factors such as limited active sites and hindered substance transport. This study successfully prepared a high-entropy sulfide (ZnCoMnFeAlMg)(9)S-8, which reduced grain size and increased specific surface area, enabling the realization of a dual-functional catalyst with multiple catalytic sites. High entropy also modulated the electronic properties of sulfides, reducing the potential energy barrier for hydrolysis. This research introduces a new approach for functionalizing high entropy nanomaterials and improves the performance of water splitting catalysts.