Article
Chemistry, Organic
Xiaoting Wen, Jingxi He, Hui Xi, Qi Zheng, Weiping Liu
Summary: A general and practical methodology for the hydration of nitriles to primary amides enabled by manganese catalyst is described. This protocol demonstrates a broad substrate scope and good functional group tolerance, allowing for the synthesis of corresponding amides in good to excellent yields. Preliminary mechanistic studies suggest the involvement of metal-ligand cooperation (MLC) mode in the catalytic process.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Physical
Ang Li, Ling Zhang, Fangzheng Wang, Li Zhang, Li Li, Hongmei Chen, Zidong Wei
Summary: The study developed a facile strategy for synthesizing highly efficient bifunctional water splitting electrocatalysts, fabricating porous Ni-Co-Fe ternary metal phosphides nanobricks with specified components and morphology, showing remarkable electrocatalytic performance in 1.0 M KOH.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2022)
Article
Nanoscience & Nanotechnology
K. S. S. V. Prasad Reddy, Parag A. Deshpande
Summary: Graphene nanosheets are robust support materials for metal nanoparticles, with double-vacancy-defected graphene and B-doped graphene identified as excellent traps for Pd-3 and Pd-4 clusters, immobilizing and hindering their surface migration for potential heterogeneous catalytic applications. The stability of clusters in the presence of H-2 also makes them suitable for catalyzing hydrogenation reactions.
ACS APPLIED NANO MATERIALS
(2021)
Article
Chemistry, Physical
Peng Zhang, Haobin Tan, Zhongkai Wang, Lai Lyu, Chun Hu
Summary: Establishing structure-activity relationship is crucial for designing catalysts with low energy consumption and high efficiency in advanced oxidation processes. This study investigates the atomic mechanism of hydrogen peroxide dissociation and formation on different zinc chalcogenides. The catalytic activity of hydrogen peroxide on zinc chalcogenides is determined by the surface micro-engineering construction including surface orientation and heteroatomic doping. These findings not only provide a better understanding of the mechanism of hydrogen peroxide on zinc chalcogenides, but also offer guidance for the development of new catalytic oxidation systems.
APPLIED SURFACE SCIENCE
(2023)
Review
Chemistry, Inorganic & Nuclear
Pascale Crochet, Victorio Cadierno
Summary: This review discusses the application of metal-based catalysts in the hydration of nitriles, with a focus on alpha- and beta-hydroxynitriles and cyanamides. It points out the lack of attention paid to this specific class of substrates compared to more classical organonitriles. The review also covers transfer hydration strategies involving water surrogates for conversion of C equivalent to N groups into C(=O)NH2 groups.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2021)
Review
Chemistry, Inorganic & Nuclear
Pengcheng Gao, Michal Szostak
Summary: The catalytic addition of water to unsaturated C-C or C-N p bonds is an important and environmentally sustainable method for forming C-O bonds. Traditional acid-catalyzed hydration requires strong acids or toxic mercury salts, limiting its practical applications and posing safety and environmental concerns. Transition-metal-catalyzed hydration with NHC ligands has gained significant attention and has achieved major progress. This review provides a comprehensive overview of hydration reactions catalyzed by transition metal-NHC complexes and their applications in catalytic hydration.
COORDINATION CHEMISTRY REVIEWS
(2023)
Article
Chemistry, Multidisciplinary
Damiano Cirri, Tiziano Marzo, Alessandro Pratesi
Summary: This article describes an unprecedented palladium/arsenic-based catalytic cycle for the hydration of nitriles to amides, which takes place under exceptionally mild conditions of neutral pH and moderate temperature (60°C). The versatility of this new catalytic cycle was tested on various nitriles, ranging from aliphatic to aromatic. The effect of ring substitution with electron withdrawing and electron donating groups, as well as potentially interferent functional groups such as hydroxy or pyridinic nitrogen, was investigated. Furthermore, a pilot study on the potential scalability of this approach for industrial production is presented, demonstrating its potential and rapid scale-up capability.
FRONTIERS IN CHEMISTRY
(2023)
Article
Chemistry, Physical
Jessi E. S. van der Hoeven, Hio Tong Ngan, Austin Taylor, Nathaniel M. Eagan, Joanna Aizenberg, Philippe Sautet, Robert J. Madix, Cynthia M. Friend
Summary: Combining experiments and theory, this study addresses the impact of Pd concentration and ensemble size on catalytic activity, activation energy, and rate-limiting processes. Results show that increasing Pd concentration in the Pd-in-Au alloy catalyst leads to a significant increase in activity with a higher apparent activation energy, suggesting a shift in ensemble size distribution towards larger Pd ensembles. Both experimental and theoretical findings support the idea that the increased reaction rate with higher Pd content and ensemble size is driven by entropy and the prevention of subsurface hydrogen formation in achieving high selectivity in hydrogenation catalysis.
Review
Chemistry, Physical
Yu Hao, Tian-Yu Sun, Liang-Feng Huang
Summary: This article reviews the role and microscopic mechanisms of defective MoS2 in electrochemical reactions from the perspective of density-functional-theory simulation. It also projects the future research trends and challenges in the electrochemical catalysis and corrosion of defective MoS2.
CURRENT OPINION IN ELECTROCHEMISTRY
(2022)
Article
Chemistry, Physical
Arghadip Ghosh, Nicolas Grimblat, Somratan Sau, Arijit Saha, Vincent Gandon, Akhila K. Sahoo
Summary: This article presents a Pd-(II)-catalyzed direct difunctionalization of two C-(sp(3))-H bonds of aliphatic carboxylic acid derivatives using bifunctional reagents (BFRs) of the 2-iodobenzoic acid series. Various directing groups, ligands, bases, and co-oxidants are employed to facilitate the reaction, leading to the formation of benzo-fused peripheral-substituted caprolactones. Mechanistic studies provide insights into the crucial steps involved in the transformation. The versatility of the complex molecular entities is also showcased.
Article
Chemistry, Physical
Ranga Rohit Seemakurthi, Griffin Canning, Zhenwei Wu, Jeffrey T. Miller, Abhaya K. Datye, Jeffrey Greeley
Summary: First principles periodic density functional theory calculations, combined with detailed microkinetic modeling and experimental characterization, were used to investigate the structure sensitivity and key selectivity descriptors for nonoxidative propane dehydrogenation (PDH) on intermetallic alloys. The study showed that Pd-terminated steps on 1:1 PdIn surfaces have significantly higher rates and selectivity towards propylene formation compared to pure Pd steps and terraces, suggesting a potential strategy for identifying selective nonoxidative PDH alloy catalysts.
Article
Chemistry, Applied
Qifeng Lei, Chang Wang, Weili Dai, Guangjun Wu, Naijia Guan, Michael Hunger, Landong Li
Summary: The study prepared bifunctional TiSn-Beta zeolite as an efficient heterogeneous catalyst for converting alkenes to 1,2-diols in a single step with high selectivity. The isolated Ti and Sn Lewis acid sites within the zeolite enabled efficient integration of alkene epoxidation and epoxide hydration in tandem reactions, showing high selectivity towards the desired product. This novel method can be applied to other tandem catalytic reactions for sustainable chemical production.
CHINESE JOURNAL OF CATALYSIS
(2021)
Article
Chemistry, Physical
Selina K. Kaiser, Jessi E. S. van der Hoeven, George Yan, Kang Rui Garrick Lim, Hio Tong Ngan, Sadhya Garg, Mustafa Karatok, Michael Aizenberg, Joanna Aizenberg, Philippe Sautet, Cynthia M. Friend, Robert J. Madix
Summary: Unraveling metal nuclearity effects is crucial for identifying active sites and developing high-performance heterogeneous catalysts. In this study, a platform of nanostructured palladium/gold alloy nanoparticles was used to assess the impact of palladium ensemble size on the catalytic performance in the hydrogenation of benzaldehyde. The results showed that Pd single atoms were inactive, while small Pd clusters exhibited optimal catalytic activity. The bimetallic catalyst also showed improved selectivity and stability compared to pure Pd nanoparticles.
Article
Materials Science, Multidisciplinary
Oriyomi Opetubo, Ayotunde Idris Ibitoye, Sunday Temitope Oyinbo, Tien -Chien Jen
Summary: This study investigates the effects of hydrogen on pure palladium and palladium-copper alloys and finds that the presence of hydrogen alters the crystalline structure. Pd-Cu alloy shows better stability and anti-hydrogen brittleness compared to pure palladium.
Article
Chemistry, Physical
Shankara S. Kalanur, Young Jae Lee, Hyungtak Seo, Bruno G. Pollet
Summary: This study investigates the introduction of hole trap states in bismuth vanadate (BiVO4) by tantalum (Ta) doping, which leads to enhanced photoelectrochemical (PEC) water-splitting activity. The doping of Ta alters the structure and chemical surroundings of BiVO4, forming hole trap states and causing lattice distortions. The photocurrent is significantly increased to 4.2 mA cm(-2) with an efficiency of 96.7%. DFT calculations confirm the decrease in optical band gap and the activation of hole trap states with the contribution of Ta, increasing charge separation and carrier density.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2023)
Article
Chemistry, Physical
Hiroe Kubota, Shinya Mine, Takashi Toyao, Ken-ichi Shimizu
Summary: In this study, Ag-loaded Al2O3 catalysts with different alumina powders were prepared and their catalytic activities were investigated for the selective catalytic reduction (SCR) of NO by NH3 or C3H6. The results showed that the activity of the catalysts and the size of the Ag metal nanoparticles changed with different alumina supports. The molecular-level insights into the design of sintering-resistant Ag/Al2O3 catalysts for SCR were provided.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Lingcong Li, Ziyang Wu, Shinta Miyazaki, Takashi Toyao, Zen Maeno, Ken-ichi Shimizu
Summary: Continuous CO2 capture and reduction for CH4 production was investigated using a double reactor system over Al2O3-supported Ni-Ca dual functional materials in the presence of O2. A high Ca loading (Ni(10)-Ca(30)/Al2O3) was found to be necessary for reaction efficiency. The optimized dual functional material showed excellent performance and stability.
Article
Energy & Fuels
Shinta Miyazaki, Zirui Li, Lingcong Li, Takashi Toyao, Yuta Nakasaka, Yasushi Nakajima, Ken-ichi Shimizu, Zen Maeno
Summary: In this study, Ni-modified tungstate zirconia (Ni/WO3/ZrO2) was developed as an effective material for chemical looping dry reforming of methane (CL-DRM) under isothermal conditions. The performance of Ni/WO3/ZrO2 was strongly influenced by the loading amount of WO3, with the optimal amount being 10.0 wt%. Increasing the loading amount to 30.0 wt% resulted in the formation of crystalline WO3 species and diminished the CL-DRM performance. Comprehensive characterization studies revealed that surface dispersed tungstate species were reduced by CH4 and reoxidized by CO2, leading to efficient CL-DRM.
Article
Chemistry, Inorganic & Nuclear
Kosuke Shimoda, Satoshi Ishikawa, Mai Miyasawa, Ken-ichi Shimizu, Wataru Ueda
Summary: In this study, a new class of high-dimensionally structured molybdenum oxide (HDS-MoO(x)) was reported, which was constructed by the random assembly of {Mo6O21}(6-) pentagonal units (PUs). HDS-MoO(x) could generate a substantial amount of lattice oxygen defects without causing crystal structure changes. It showed higher oxidation ability compared to typical molybdenum oxide.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Physical
Ke Liu, Feilong Xing, Yiying Xiao, Ning Yan, Ken-ichi Shimizu, Shinya Furukawa
Summary: A pseudo-binary alloy catalyst (Ni0.5Co0.5)3Ge/SiO2 has been developed to improve the durability and reusability of dry reforming of methane. The formation of pseudo-binary alloy structure was confirmed through various characterization techniques. The alloy exhibited high catalytic activity and remarkable thermal stability even below the equilibrium conversion, which was attributed to the optimal modification of C-H activation ability by doping Co to Ni3Ge.
Article
Chemistry, Physical
Meilin Tao, Satoshi Ishikawa, Takuji Ikeda, Shunsaku Yasumura, Kosuke Shimoda, Ryota Osuga, Yuan Jing, Takashi Toyao, Ken-ichi Shimizu, Hiromi Matsuhashi, Wataru Ueda
Summary: In this study, the crystal structure and acid properties of Zr3SO9 were investigated. It was found that Zr3SO9 exhibited excellent catalytic activity for acid reactions, surpassing typical acid catalysts. The introduction of H2O transformed the acid sites of Zr3SO9, resulting in a shift from Lewis to Bronsted acid sites.
Article
Chemistry, Physical
Ningqiang Zhang, Shinta Miyazaki, Yucheng Qian, Yuan Jing, Takashi Toyao, Ken-ichi Shimizu
Summary: Kinetic analyses of Ce4+ <-> Ce3+ redox and CO2/H-2 formation for the unsteady-state water-gas shift (WGS) reaction are carried out on Cu/CeO2 catalysts under periodic CO <-> H2O feeds at 350 degrees C. The results provide quantitative evidence of the redox-based mechanism of the reaction and suggest that Ce3+- reoxidation by H2O has a lower barrier than Ce4+-O reduction. The number of interfacial sites between CeO2 and Cu species affects the turnover frequencies for the redox reaction and CO2/H-2 formation. An associative redox mechanism based on the redox reaction between Cu2+-OH and Ce4+-OH/Ce4+ and Cu+--Ce3+ is proposed as the main catalytic cycle of the reaction.
Article
Engineering, Environmental
Ningqiang Zhang, Jiahuan Tong, Shinta Miyazaki, Shirun Zhao, Hiroe Kubota, Yuan Jing, Shinya Mine, Takashi Toyao, Ken-ichi Shimizu
Summary: This study investigates the active sites and reaction mechanism for the selective catalytic reduction of NO by NH3 over phosphate-loaded ceria catalysts. The results reveal the presence of H3PO4 and H2P2O6 species on the catalysts, which interact with Ce4+(OH-) species and undergo reduction/oxidation half-cycles to produce N2, H2O, and Ce3+ species.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Can Liu, Bang Lu, Hiroko Ariga-Miwa, Shohei Ogura, Takahiro Ozawa, Katsuyuki Fukutani, Min Gao, Jun-ya Hasegawa, Ken-ichi Shimizu, Kiyotaka Asakura, Satoru Takakusagi
Summary: In this study, the dynamic behavior of methoxy intermediate on a Pt/TiO2(110) surface during methanol decomposition has been investigated using STM, TPD, and DFT calculations. The results showed that the methoxy intermediates migrate on the TiO2 support surface to seek and find active Pt sites. This work provides a deeper understanding of the role of intermediate adsorbate migration in controlling the catalytic performance.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Shunsaku Yasumura, Takashi Kamachi, Takashi Toyao, Ken-ichi Shimizu, Yoyo Hinuma
Summary: This study proposes the unsaturated coordination index, σ, as a potential descriptor for the stability of metal-oxide surfaces. The value of σ, representing the number of missing bonds per unit area, can be quickly obtained using only crystallographic data, specifically the bulk geometry. The calculated surface energies of various binary oxides show good correlations with σ, particularly in high-symmetry crystals. This descriptor is useful for an initial evaluation of stable metal-oxide surfaces without the need for surface model calculations.
Article
Engineering, Environmental
Lingcong Li, Ningqiang Zhang, Ziyang Wu, Shinta Miyazaki, Takashi Toyao, Zen Maeno, Ken-ichi Shimizu
Summary: Ni-based dual-functional materials (DFMs) have been extensively studied for CO2 capture and reduction with H2 (CCR); however, controlling the selectivity of CO2 hydrogenation to CH4 or CO is a challenge; in this study, Rb-Ni/Al2O3 is developed as an effective DFM for selective CO production through CCR at isothermal conditions, achieving high CO2 conversion and CO selectivity.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Engineering, Environmental
Ningqiang Zhang, Yucheng Qian, Takashi Toyao, Ken-ichi Shimizu
Summary: This article reports a new de-NOx system that uses cyclic feeds of rich and lean gas mixtures with PGM-free catalysts, showing higher NOx conversion compared to steady-state reactions. The mechanism under periodical rich/lean conditions was studied and a new urea-free and PGM-free catalytic system was demonstrated.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Physical
Mengwen Huang, Yosuke Tomimuro, Shinta Miyazaki, Shinya Mine, Takashi Toyao, Yoyo Hinuma, Yasuharu Kanda, Masaaki Kitano, Ken-ichi Shimizu, Zen Maeno
Summary: This study investigates propane metathesis reactions over metal hydrides, with TiH2 showing the highest butane yield. Fully-hydrogenated TiH2 is more active than dehydrogenated TiH and Ti metal. Surface low-valent Ti species on TiH2 are involved in the propane metathesis reaction. This study is the first to observe carbon-carbon bond cleavage and catalytic formation over bulk metal hydrides.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Physical
Mengwen Huang, Tetsuya Kinjo, Shunsaku Yasumura, Takashi Toyao, Daiju Matsumura, Hiroyuki Saitoh, Ken-ichi Shimizu, Norikazu Namiki, Zen Maeno
Summary: This study investigates the catalytic performance of Ga-exchanged zeolites at actual operating temperatures using in situ analysis. The results show that Ga-exchanged zeolites exhibit higher absorption peak intensity under hydrogen and ethane atmospheres, indicating the importance of hydride species in their catalytic activity.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Physical
Mengwen Huang, Yosuke Tomimuro, Shinta Miyazaki, Shinya Mine, Takashi Toyao, Yoyo Hinuma, Yasuharu Kanda, Masaaki Kitano, Ken-ichi Shimizu, Zen Maeno
Summary: This study investigated propane metathesis reactions over group 2-5 metal hydrides, with TiH2 showing the highest butane formation. Fully-hydrogenated TiH2 was found to be more active than dehydrogenated TiH and Ti metal. Surface low-valent Ti species on TiH2 were involved in the propane metathesis reaction. This study represents the first example of carbon-carbon bond cleavage and catalytic formation over bulk metal hydrides.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)