Review
Chemistry, Multidisciplinary
Allison M. Arinaga, Morgan C. Ziegelski, Tobin J. Marks
Summary: Research on the catalytic oxidative coupling of methane (OCM) using alternative oxidants such as N2O, CO2, and S-2 is still in its early stages, with unique advantages and challenges compared to oxygen (O-2) as the oxidant. This area has not been extensively reviewed, despite the renewed interest in OCM due to the abundance of shale gas resources.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Applied
P. Saychu, M. Thanasiriruk, C. Khajonvittayakul, R. Viratikul, V. Tongnan, M. Hartley, S. Wongsakulphasatch, N. Laosiripojana, U. W. Hartley
Summary: The NaCl-Mn2O3/SiO2 catalyst showed the best performance in the OCM reaction, with high methane conversion and C-2 selectivity. However, slight deactivation was observed due to the decomposition of NaCl, leading to a decrease in chloride content and carbon formation. Na2WO4-Mn2O3/SiO2 exhibited good stability and no coke deposition, suggesting high surface oxygen content in Na2WO4.
Article
Chemistry, Physical
Jaesung Kim, Yu Jin Kim, Matthew Ferree, Seval Gunduz, Anne C. Co, Minkyu Kim, Umit S. Ozkan
Summary: This study introduces an in-situ reduction method for modifying the surface properties of lanthanum strontium cobalt ferrite (LSCF) perovskite and enhancing its electrocatalytic reactivity for oxidative coupling of methane (OCM). The formation of CoFe nanoparticles during the reduction process contributes to the high selectivity of LSCF for C2+ hydrocarbons. In-situ DRIFTS experiments demonstrate that reducing LSCF can effectively inhibit the complete oxidation of CH4, thus enabling the selective conversion of CH4 to higher order hydrocarbons.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2023)
Article
Chemistry, Physical
Yue Wang, Xiao Yang, Chenxiao Hou, Fumin Yin, Guowei Wang, Xiaolin Zhu, Guiyuan Jiang, Chunyi Li
Summary: The partial substitution of Sr with Ba in SrTiO3 perovskite was shown to enhance the catalytic performance, with improved activity and stability in OCM reaction. This improvement was mainly attributed to the reduced crystal size, increased surface chemisorbed oxygen species, and better thermal resistance of nano-sized Ba0.5Sr0.5TiO3 perovskite.
Article
Physics, Condensed Matter
Rongguang Gan, Yoshihide Nishida, Masaaki Haneda
Summary: This study investigates the effect of B site element in LaBO3 perovskites on the catalytic performance for the oxidative coupling of methane reaction. LaAlO3, LaGaO3, LaInO3, and LaYbO3 catalysts exhibit higher activity in the formation of C-2 hydrocarbons in the reaction. The study reveals that the formation of CH3·, as the first step in the reaction, is strongly influenced by the B site element.
PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS
(2022)
Article
Engineering, Environmental
R. S. Postma, P. S. F. Mendes, L. Pirro, A. Banerjee, J. W. Thybaut, L. Lefferts
Summary: The interplay between catalytic activation of methane on Fe (c) SiO2 and gas-phase free radical methane coupling under non-oxidative conditions is analyzed by mechanistic modeling and experiments. The model validates the significant contribution of gas-phase reactions responsible for methane conversion and the low-activity induction period in gas-phase methane pyrolysis can be overcome by catalytic activation. Gas-phase reactions determines the selectivity distribution while catalytic reaction only influences the activity of the system.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Lingjun Hu, Donato Pinto, Atsushi Urakawa
Summary: The temperature and concentration gradients are of great relevance in the selectivity limitation of oxidative coupling catalysis for methane valorization. Through spatially resolved operando analysis, it is revealed that the highly exothermic reactions in the gas phase, i.e. homogeneous reactions, at the front of the catalytic bed play a crucial role in determining the total C-2 yield. The addition of promoters can suppress the exothermic oxidation paths, leading to the desired C(2) products.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2023)
Article
Chemistry, Physical
Meng-Nan Zhu, Bo-Wen Zhang, Min-Rui Gao, Peng-Fei Sui, Chenyu Xu, Lu Gong, Hongbo Zeng, Karthik Shankar, Steven Bergens, Jing-Li Luo
Summary: This study reveals that the reconstructed BaBiO3 perovskite can facilitate CO2-to-formate conversion through cooperative catalysis between A (Ba) and B (Bi) site elements. The electrochemical reduction triggers atom rearrangement and generates efficient Bi metallene, while the release of Ba2+ promotes CO2 adsorption and conversion.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2022)
Article
Engineering, Chemical
Faisal Alahmadi, Anastasiya Bavykina, Daria Poloneeva, Adrian Ramirez, Robert Schucker, Jorge Gascon
Summary: Since its discovery in 1982, oxidative coupling of methane (OCM) has been considered a promising method for synthesizing ethylene. In this study, undoped neodymium oxide and neodymium oxide doped with different levels of strontium were tested under various operating conditions. The results showed that the catalysts achieved C2+ yields greater than 18%, with the space velocity impacting C2+ selectivity. The difference in activity between the catalysts was attributed to the contribution of different oxygen centers.
Article
Engineering, Chemical
Jian Song, Claudia Li, Shao Zhang, Xiuxia Meng, Bo Meng, Jaka Sunarso
Summary: The study evaluated the effects of adding BCG and BSCF catalyst layers on LSCF hollow fibers, demonstrating the complex interplay between oxygen permeation and OCM performance.
CHINESE JOURNAL OF CHEMICAL ENGINEERING
(2022)
Article
Engineering, Environmental
Tsegay Gebrekidan Gebreyohannes, Sung Woo Lee, Seung Ju Han, Yong Tae Kim, Seok Ki Kim
Summary: This study developed a detailed mechanism for non-oxidative coupling of methane (NOCM), consisting of 1,112 species and 106,877 gas-phase reactions. A reduced mechanism with 178 species and 9,695 reactions was obtained, focusing on four target products. The evaluation of methane conversion and species concentration revealed the significant impact of temperature and pressure.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Thermodynamics
Seokwon Cho, Hyewon Lee, Ying Lin, Satbir Singh, William F. Northrop
Summary: Pretreating natural gas using catalytic oxidative coupling of methane (OCM) can produce ethylene and ethane, increasing fuel reactivity and expanding the operational range of highly efficient compression ignition combustion in natural gas engines. This study presents experimental and computational results on the impact of OCM product species on engine thermal efficiency and operability range.
ENERGY CONVERSION AND MANAGEMENT
(2022)
Article
Chemistry, Physical
Anna Zanina, Vita A. Kondratenko, Henrik Lund, Jianshu Li, Juan Chen, Yuming Li, Guiyuan Jiang, Evgenii Kondratenko
Summary: This study shows that MnOx-Na2WO4/SiO2 is not the necessary catalyst to achieve high selectivity in the oxidative coupling of methane. Experimental results reveal that M2WO4/SiO2 materials perform similarly to MnOx-Na2WO4/SiO2 in terms of selectivity and conversion. An alternative concept is proposed, suggesting that the activity and product selectivity of M2WO4/SiO2 are determined by the interaction between lattice oxygen of M2WO4 and adsorbed oxygen species from the gas phase.
Article
Chemistry, Physical
Heeyeon Kim, Suhyeong Lee, Seoyoung Jang, Ji-haeng Yu, Jong Suk Yoo, Jangwon Oh
Summary: In this study, a simple pyridine treatment of NaW/Mn/SiO2 led to nitrogen-doping of the active sites, resulting in significantly improved CH4 conversion rate and high C-2 selectivity. Various characterization techniques were employed to understand the effect of N doping on the performance of NaW/Mn/SiO2 for OCM, providing new insights for improving catalytic performance in OCM reactions.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2021)
Article
Chemistry, Physical
Jiawei Hu, Vladimir V. Galvita, Hilde Poelman, Zhigang Wang, Guy B. Marin, Sibudjing Kawi
Summary: By utilizing carbon's reductive power, this study integrates dry reforming of methane and selective reduction of nitric oxide in a chemical looping process, achieving stable CO2 utilization and NO reduction with cyclic catalyst regeneration. The temporal-spatial separation of reactions in chemical looping allows for complete conversion of carbon and NO, ensuring a higher exergetic efficiency. Additionally, adapting the relative duration of the DRM and SRN steps to industrial point sources offers an attractive strategy for selective catalytic reduction of NO with greenhouse gases.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2021)
Article
Chemistry, Physical
Keiju Wachi, Tomohiro Yabe, Takaaki Suzuki, Kentaro Yonesato, Kosuke Suzuki, Kazuya Yamaguchi
Summary: This study successfully formed thermally stable FeOx subnanoclusters on SiO2 using a diiron-introduced polyoxometalate as a precursor, which selectively converted methane into formaldehyde and carbon monoxide. The catalyst maintained stable catalytic activity even under high temperature conditions.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2022)
Article
Chemistry, Physical
Takehiro Matsuyama, Takafumi Yatabe, Tomohiro Yabe, Kazuya Yamaguchi
Summary: A versatile 1,2-diketone decarbonylation to produce diaryl ketones was achieved using a CeO2-supported Au-Pd alloy nanoparticle catalyst. The high catalytic performance was attributed to the promotion of reductive elimination by electron-deficient Pd(0) species interacting strongly with CeO2 and the suppression of catalyst deactivation through Pd alloying with Au.
Article
Chemistry, Multidisciplinary
Takaaki Suzuki, Tomohiro Yabe, Keiju Wachi, Kentaro Yonesato, Kosuke Suzuki, Kazuya Yamaguchi
Summary: We developed a new preparation method to obtain highly dispersed metal-oxo cluster Cs salts via cation exchange from the corresponding TBA salts on supports. Various characterizations revealed that the method maintained the stability and structure of the metal-oxo clusters under high temperature and aerobic conditions.
Article
Chemistry, Multidisciplinary
Hiroshi Sampei, Koki Saegusa, Kenshin Chishima, Takuma Higo, Shu Tanaka, Yoshihiro Yayama, Makoto Nakamura, Koichi Kimura, Yasushi Sekine
Summary: Quantum annealing is used to predict molecular adsorption on solid surfaces. The evaluation of adsorption is crucial for various fields, but it is challenging to predict the stable coordination for multi-molecular adsorption. This report presents a novel method that uses the quantum annealing principle to quickly search for adsorption coordination, providing faster search speed and more stable molecular arrangement findings than conventional methods.
Article
Chemistry, Multidisciplinary
Keke Kang, Sota Kakihara, Takuma Higo, Hiroshi Sampei, Koki Saegusa, Yasushi Sekine
Summary: In this study, it was found that the reverse water gas shift (RWGS) reaction can be carried out at low temperatures without equilibrium constraints using chemical looping (CL) method. With the newly developed MGa2Ox materials, almost 100% CO2 conversion was achieved at temperatures as low as 673 K, greatly reducing the cost for CO2 separation. This finding is a significant advancement for the future utilization of CO2.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Yasushi Sekine
Summary: Low-temperature ammonia synthesis using a solid heterogeneous catalyst under the influence of an electric field was studied. The reaction efficiency was improved by the associative mechanism facilitated by proton-conducting species on the catalyst support surface, leading to the formation of N2Had intermediates. Various analysis techniques were employed to investigate the role of metal and catalyst support structure, and computational chemistry was used for further analysis. The study showed that the catalytic activity shifted from N-2 dissociation to N2H formation, resulting in efficient ammonia synthesis at low temperatures even with base metal catalysts like Fe and Ni.
FARADAY DISCUSSIONS
(2023)
Article
Chemistry, Multidisciplinary
Ayaka Motomura, Yuki Nakaya, Clarence Sampson, Takuma Higo, Maki Torimoto, Hideaki Tsuneki, Shinya Furukawa, Yasushi Sekine
Summary: Dry reforming of methane (DRM) is a promising reaction for converting greenhouse gases into syngas. By applying an electric field and using Ni-Fe bimetallic catalysts, the difficulties in conventional thermal catalytic reactions can be overcome.
Article
Chemistry, Multidisciplinary
Taku Matsuda, Ryo Ishibashi, Yoshiki Koshizuka, Hideaki Tsuneki, Yasushi Sekine
Summary: This study provides a quantitative analysis of oxide surface protonics in a dry H-2 atmosphere. The results show that the conductivity of porous CeO2 increases significantly when H-2 is supplied, with dissociative adsorption of H-2 playing a key role in conduction.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Kaho Nagakawa, Hiroshi Sampei, Ayako Takahashi, Jun Sasaki, Takuma Higo, Naoya Mori, Hideto Sato, Yasushi Sekine
Summary: The effect of OH-groups on the surface of a Ni catalyst for low-temperature steam reforming of methane in an electric field was investigated. It was found that adding hydrogen and steam in the pre-treatment, as well as the presence of an electric field, can enhance the catalyst activity by increasing the surface OH-groups and Ni(OH)2 content, thereby improving the surface proton conduction.
Article
Chemistry, Multidisciplinary
Kosuke Watanabe, Takuma Higo, Hideaki Tsuneki, Shun Maeda, Kunihide Hashimoto, Yasushi Sekine
Summary: This study found that the perovskite oxide YCrO3 exhibits higher catalytic activity and C2H4 selectivity in the presence of steam, which is significant for improving the efficient production of ethylene. Steam plays an important role in stabilizing the catalyst's high activity and inhibiting coke accumulation.
Article
Chemistry, Analytical
Hiroki Ishida, Naoki Yamasaki, Yuuki Otsuka, Daichi Mori, Tomoko Shimamura, Takuya Hasegawa, Shuhei Ogo, Tadaharu Ueda
Summary: An on-site electrochemical antioxidant capacity measurement system was developed and compared with spectroscopic methods and conventional electrochemical methods. The system showed promising results and was able to measure the antioxidant capacities of various antioxidants and vegetable extracts quickly and accurately.
ANALYTICAL SCIENCES
(2022)
Article
Chemistry, Multidisciplinary
Naoya Nakano, Maki Torimoto, Hiroshi Sampei, Reiji Yamashita, Ryota Yamano, Koki Saegusa, Ayaka Motomura, Kaho Nagakawa, Hideaki Tsuneki, Shuhei Ogo, Yasushi Sekine
Summary: This study investigates the effect of an electric field on the dry reforming of methane. The results show that the application of an electric field significantly enhances the conversion rate of methane and carbon dioxide, and promotes the reaction between surface oxygen and methane at the Pt and CeO2 interface.
Article
Chemistry, Multidisciplinary
Jun-Ichiro Makiura, Sota Kakihara, Takuma Higo, Naoki Ito, Yuichiro Hirano, Yasushi Sekine
Summary: The conversion of CO2 to CO by reverse water-gas shift using chemical looping is an efficient process for CO production, and Co-In2O3 has been developed as a suitable oxygen storage material for this process, showing high CO2 splitting rate and durability.
CHEMICAL COMMUNICATIONS
(2022)
Review
Chemistry, Physical
Maki Torimoto, Yasushi Sekine
Summary: This article provides an overview of recent research on alloy catalysts, which have excellent catalytic performance in methane reforming reactions. Alloy catalysts can improve activity, stability, and resistance to carbon deposition, making them highly promising for various applications.
CATALYSIS SCIENCE & TECHNOLOGY
(2022)
