Article
Chemistry, Physical
Edward Ocansey, James Darkwa, Banothile C. E. Makhubela
Summary: Novel Ir half-sandwich complexes with N^N bidentate ligands were synthesized and found to exhibit high activity in CO2 hydrogenation, producing formate. Proton responsive groups on the catalysts influence the reaction mechanism.
MOLECULAR CATALYSIS
(2022)
Article
Chemistry, Inorganic & Nuclear
Daehan Lee, Sunghan Choi, Min Su Choe, So-Yoen Kim, Kyutai Park, Chul Hoon Kim, Ho-Jin Son, Sang Ook Kang
Summary: The catalytic performance of the half-metallocene Ir(III) complex in photochemical CO2 reduction was evaluated in both homogeneous and heterogeneous systems. Modification of the catalyst and photosensitizer led to the formation of mixed homogeneous and heterogeneous ternary hybrid systems, revealing two different catalytic routes for CO2 reduction. Experimental and theoretical studies suggested that the homogeneous catalysis involves a Cp*Ir-III-H intermediate, while the heterogeneous catalysis undergoes multiple electron transfer pathways.
Article
Chemistry, Inorganic & Nuclear
Edward Ocansey, James Darkwa, Banothile C. E. Makhubela
Summary: Bimetallic catalytic systems, particularly heterogeneous ones, have been found to be effective for CO2 hydrogenation due to synergistic effects. These systems can catalyze the reduction of CO2 to formate selectively. Ir-Sn catalysts can effectively hydrogenate CO2 directly or bicarbonate ions formed in solution during the catalytic cycle.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2021)
Article
Chemistry, Inorganic & Nuclear
Lan Mei, Min Du, Yuan Zhang, Cheng Hou
Summary: This study investigates the mechanistic preference of a ruthenium complex with dual proton-responsive sites in borrowing-hydrogen N-alkylation catalysis using DFT calculations. The results suggest that the gamma-NH site facilitates the rate-determining step via non-covalent interaction, while the alpha-NH site requires overcoming a higher activation energy barrier.
DALTON TRANSACTIONS
(2022)
Article
Chemistry, Physical
Zhihong Wei, Xinxin Tian, Michael Bender, Matthias Beller, Haijun Jiao
Summary: The study investigates the mechanisms of CO2 and H-2 conversion in methanol to dimethoxymethane catalyzed by [(PCo)-Co-3-H](+) catalyst and HNTf2 cocatalyst. It reveals that the rate-determining step involves methylating CH3OCH2OH with CH3-NTf2, and the reaction kinetics is controlled by both metal catalyst and acid cocatalyst.
Article
Chemistry, Multidisciplinary
Ryoichi Kanega, Naoya Onishi, Shinji Tanaka, Haruo Kishimoto, Yuichiro Himeda
Summary: A novel approach using multinuclear iridium complexes for catalytic hydrogenation of CO2 to methanol in the gas-solid phase was reported. The combination of a multinuclear catalyst and gas-solid phase reaction conditions led to effective production of methanol. The catalyst showed high reactivity, with a final turnover number of 113 under specific conditions.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Multidisciplinary Sciences
Jinling Hu, Wentao Ma, Qiang Liu, Jiao Geng, Youting Wu, Xingbang Hu
Summary: This article reports a method for the selective and efficient hydrogenation of CO2 to formic acid under neutral conditions using a heterogeneous catalyst and imidazolium chloride ionic liquid as the solvent. This method can avoid waste production and simplify product separation, and exhibits high catalytic activity and stability.
Article
Chemistry, Multidisciplinary
Lei Zhou, Chenfei Yao, Wentao Ma, Jinling Hu, Youting Wu, Zhibing Zhang, Xingbang Hu
Summary: The polymerization method was used to prepare the PCAAC-Ir catalyst, which showed excellent stability and activity in CO2 hydrogenation reaction, with a yield 38.7 times higher than the un-polymerized CAAC-Ir. Moreover, the catalyst performs well in water and can be easily recycled without significant loss of activity.
JOURNAL OF CO2 UTILIZATION
(2021)
Article
Chemistry, Inorganic & Nuclear
Xiu-Fang Mo, Shun Ge, Ping-Ping Yi, Guo Chen, Jia-Hao Liu, Chao Liu, Xiao-Yi Yi, Piao He
Summary: A series of Cp*Ir complexes with N^N or N^O ancillary ligands were designed and synthesized, and it was found that the pendant base in metal complexes plays a key role in rate-determining heterolytic H2 splitting and enhancing the proton transfer, thereby improving the catalytic activity.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Physical
Yeon-Joo Cheong, Kihyuk Sung, Jin-A Kim, Yu Kwon Kim, Woojin Yoon, Hoseop Yun, Hye-Young Jang
Summary: The iridium(NHC)-catalyzed transfer hydrogenation of CO2 and inorganic carbonates with glycerol showed excellent turnover numbers and turnover frequencies for the formation of formate and lactate under high temperature conditions. Iridium catalysts modified with the triscarbene ligand demonstrated outstanding catalytic activity at 200 degrees C, making them a suitable choice for high TONs of formate. The proposed transfer hydrogenation mechanism of CO2 was based on control experiments.
Article
Chemistry, Multidisciplinary
Stanislav Gelman-Tropp, Evgueni Kirillov, Evamarie Hey-Hawkins, Dmitri Gelman
Summary: Formic acid, as a stable and harmless chemical substance, is crucial for reversible hydrogen storage in a fossil fuels-free economy. This manuscript reports the successful application of a redesigned catalyst for mild hydrogenation of CO(2) to formic acid, showing high TON and TOF values. The experimental and computational mechanistic studies provide a rationale for the design of next-generation catalysts.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Physical
Sheng-Mei Lu, Meng-Meng Wang, Xiangfeng Lin, Can Li
Summary: This article reports an efficient iridium catalyst for the hydrogenation of alkyl carboxylic acids to alcohols and esters under mild conditions without any additives. Among the evaluated catalysts, complex 4 shows the highest performance with a TON of 1106 for acetic acid hydrogenation.
Article
Chemistry, Applied
Kihyuk Sung, Mi-hyun Lee, Yeon-Joo Cheong, Hye-Young Jang
Summary: Sustainable iridium-catalyzed transfer hydrogenation using glycerol as the hydride source was employed to convert levulinic acid to gamma-valerolactone with exceptionally high turnover numbers and turnover frequencies. The triscarbene-modified iridium catalysts showed good catalytic activities and recyclability. In addition, several alcohol compounds were also successfully applied to convert levulinic acid to gamma-valerolactone.
APPLIED ORGANOMETALLIC CHEMISTRY
(2021)
Article
Polymer Science
Wenhui Ren, Fen You, Jingjing Zhai, Xiaohui Kang, Yat-Ming So, Xiaochao Shi
Summary: This study presents a single rare-earth metal catalyst that can promote the polymerization of isoprene and butadiene with unmatched stereoselectivity, resulting in polymers with different cis or trans structures. Moreover, the catalyst allows for the precise control of diblock and multiblock copolymers with differently stereoselective adjacent blocks. The mechanical properties of the produced block copolymers can be tailored by controlling the sequence length.
Article
Chemistry, Multidisciplinary
Josep Mas-Rosello, Christopher J. Cope, Eric Tan, Benjamin Pinson, Alan Robinson, Tomas Smejkal, Nicolai Cramer
Summary: Cyclometalated cyclopentadienyl iridium(III) complexes are efficient catalysts in the hydrogenation of oximes, with alkoxy-substituted aryl ketimine ligands providing the best catalytic performance. The stable iridium C,N-chelation is crucial for the catalytic activity, and the hydrogenation system demonstrates high functional group compatibility.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Ryoichi Kanega, Naoya Onishi, Shinji Tanaka, Haruo Kishimoto, Yuichiro Himeda
Summary: A novel approach using multinuclear iridium complexes for catalytic hydrogenation of CO2 to methanol in the gas-solid phase was reported. The combination of a multinuclear catalyst and gas-solid phase reaction conditions led to effective production of methanol. The catalyst showed high reactivity, with a final turnover number of 113 under specific conditions.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Review
Chemistry, Multidisciplinary
Etsuko Fujita, David C. Grills, Gerald F. Manbeck, Dmitry E. Polyansky
Summary: The conversion of carbon dioxide to fuels and chemicals is a promising strategy for renewable energy storage. Molecular catalysts, particularly coordination complexes of transition metals, play a crucial role in the photo- and electrochemical reduction of CO2. The interactions between catalytic intermediates and promoting factors, such as acids and solvents, have a significant impact on the efficiency of catalysis. Mechanistic studies are essential for the design and improvement of efficient catalysts.
ACCOUNTS OF CHEMICAL RESEARCH
(2022)
Review
Biochemistry & Molecular Biology
Naoya Onishi, Ryoichi Kanega, Hajime Kawanami, Yuichiro Himeda
Summary: This article provides an overview of recent advances in the research on hydrogen generation by formic acid dehydrogenation, focusing primarily on the development of homogeneous catalysts, which can accelerate the transition to a hydrogen-based society.
Review
Chemistry, Physical
Mingxu Liu, Yuankang Xu, Yu Meng, Lijiao Wang, Hang Wang, Yichao Huang, Naoya Onishi, Lin Wang, Zhuangjun Fan, Yuichiro Himeda
Summary: Given the drastic increase of global carbon dioxide, renewable energy is crucial for maintaining worldwide economic growth. This review focuses on the development of a hydrogen storage system based on formic acid (FA) through CO2 hydrogenation and FA dehydrogenation. Metal catalysts at the nanoscale and single-atom scale are highlighted, as well as the effects of metal size on catalytic activities. The review also emphasizes the structure-activity relationships of various supported catalysts and provides mechanistic insights for rational catalyst design.
ADVANCED ENERGY MATERIALS
(2022)
Article
Multidisciplinary Sciences
Yuichi Manaka, Yuki Nagata, Keisuke Kobayashi, Daisuke Kobayashi, Tetsuya Nanba
Summary: This paper investigates a simple screening method for catalysts that can be used for renewable energy by combining three catalyst evaluation methods. The combination of evaluation methods can intuitively provide the necessary information for catalyst screening.
SCIENTIFIC REPORTS
(2022)
Review
Chemistry, Inorganic & Nuclear
Naoya Onishi, Yuichiro Himeda
Summary: This paper summarizes the catalysts used in methanol synthesis and dehydrogenation processes, and discusses the potential of these methods for reducing atmospheric CO2 concentration.
COORDINATION CHEMISTRY REVIEWS
(2022)
Article
Chemistry, Physical
Keisuke Kobayashi, Yuichi Manaka, Tetsuya Nanba
Summary: The conversion of nitrogen monoxide (NO) to ammonia (NH3) over copper (Cu) catalysts was investigated. It was found that Cu/CeO2 exhibited high NH3 selectivity for the NO-CO-H2O reaction at temperatures above 150 degrees C, while NH3 formation in the NO-H2 reaction was almost negligible at this temperature. The enhancement of the water-gas shift reaction was proposed to be effective in the conversion of NO to NH3.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Inorganic & Nuclear
Wan-Hui Wang, Wei-Yu Shao, Jia-Yue Sang, Xu Li, Xiaoqiang Yu, Yoshinori Yamamoto, Ming Bao
Summary: This article describes an efficient direct N,N-dialkylation of acyl hydrazide using methanol or ethanol as the alkyl reagent under weak base conditions catalyzed by amidato iridium complexes bearing an electron-donating group in the ligand. A wide range of acyl hydrazide derivatives are successfully converted into the corresponding N,N-dialkylated products in excellent yields. The experimental results suggest that ortho electron-donating groups on the phenyl moiety of the picolinamide ligand play a crucial role in the catalytic activity.
Article
Multidisciplinary Sciences
Wade C. Henke, Yun Peng, Alex A. Meier, Etsuko Fujita, David C. Grills, Dmitry E. Polyansky, James D. Blakemore
Summary: Protonation reactions of organometallic complexes often generate reactive metal hydrides. However, some organometallic species with Cp* ligands have been found to undergo ligand-centered protonation, leading to the generation of complexes with Cp*H ligands. This study investigates the kinetics and atomistic details of the protonation steps using time-resolved pulse radiolysis and stopped-flow spectroscopy. The results reveal the formation of an elusive hydride complex, Cp*Rh(H)(bpy), via the initial protonation, which further undergoes tautomerization to form Cp*H Rh(bpy). The spectroscopic monitoring of the reaction also shows that both the hydride and Cp*H complex can participate in further reactivity. The mechanistic roles of these intermediates provide insights for the design of catalytic systems using non-innocent cyclopentadienyl-type ligands.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Article
Chemistry, Multidisciplinary
Ryoichi Kanega, Erika Ishida, Takaaki Sakai, Naoya Onishi, Akira Yamamoto, Hiroki Yasumura, Hisao Yoshida, Hajime Kawanami, Yuichiro Himeda, Yukari Sato, Akihiro Ohira
Summary: This paper reports a flow battery system using CO2 and formate for storage and generation of electricity, exhibiting good cycle stability and high discharge capacity.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Xin Liu, Wen-Zhe Dong, Yining Liu, Wei-Yu Shao, Yang Li, Xiaoqiang Yu, Yuichiro Himeda, Wan-Hui Wang, Ming Bao
Summary: Transition-metal-catalyzed acceptorless dehydrogenative coupling (ADC) is a sustainable strategy for synthesizing N-heteroaromatics. Water-soluble amidato Ru catalysts were designed, synthesized, and used to selectively synthesize 2-substituted benzimidazoles and 2-substituted quinolines via the ADC strategy in water. Catalyst 1d with a strong electron-donating hydroxyl group showed the best catalytic activity.
Article
Chemistry, Multidisciplinary
Yoshihiro Goto, Masashi Kikugawa, Keisuke Kobayashi, Yuichi Manaka, Tetsuya Nanba, Hideyuki Matsumoto, Mitsuru Matsumoto, Masakazu Aoki, Haruo Imagawa
Summary: A facile method was developed to prepare BaTiO2.5H0.5 oxyhydride nanoparticles on a TiH2 surface via the conventional wet impregnation method using TiH2 and Ba hydroxide. The Ru-loaded catalyst Ru/BaTiO2.5H0.5-TiH2 exhibited significantly higher ammonia synthesis activity than the benchmark Ru catalyst Ru-Cs/MgO due to the suppression of hydrogen poisoning. This study demonstrated the importance of appropriate raw material selection for the formation of BaTiO2.5H0.5 oxyhydride nanoparticles using the conventional synthesis method.
Article
Chemistry, Physical
Siming Ding, Yuichi Manaka, Masayuki Nambo, Wang-Jae Chun, Ikuyoshi Tomita, Ken Motokura
Summary: We have developed a mesoporous-silica-supported Pd complex catalyst that promotes the Tsuji-Trost allylation of dicarbonyl compounds with allylic alcohols. By doping the silicate backbone with aluminum, the acidity of the support is increased, leading to enhanced catalytic activity in allylation.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Physical
Naoya Onishi, Yuichiro Himeda
Summary: CO2 conversion is a vital technology for reducing emissions, and methanol production from CO2 using organometallic catalysts shows promise due to its advantages compared to heterogeneous catalysts. This article provides an overview of the current state of both indirect and direct methods for methanol production from CO2, focusing on the design of organometallic catalysts and reaction processes.
Article
Chemistry, Multidisciplinary
Yuanyuan Kong, Siming Ding, Koichiro Endo, Kiyotaka Nakajima, Yuichi Manaka, Wang-Jae Chun, Ikuyoshi Tomita, Ken Motokura
Summary: The Rh-catalyzed 1,4-addition reaction of arylboronic acid is crucial in the synthesis of beta-arylcarbonyl compounds. This study immobilized Rh complexes and organic functional groups on mesoporous silica, resulting in significantly improved catalytic activity and yield in water. The catalyst showed broad applicability to a variety of arylboronic acids and enones.