Thermochemical analysis of Mo-C-H system for synthesis of molybdenum carbides

Journal Article · Tue Mar 26 00:00:00 EDT 2019 · Thermochimica Acta

DOI:https://doi.org/10.1016/j.tca.2019.03.033· OSTI ID:1597340

Nayak, Shanti Kiran ^[1]; Benavidez, Angelica D. ^[1]; Gonzales, Ivana  ^[2]; Garzon, Fernando H. ^[1]

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1. Univ. of New Mexico, Albuquerque, NM (United States)
2. Univ. of New Mexico, Albuquerque, NM (United States); Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

Earth abundant materials such as molybdenum carbide are gaining importance over expensive, precious metals such as ruthenium and platinum as catalysts for heterogeneous and electrochemical reaction systems. Despite its attributes, molybdenum carbide has not been developed as a commercial catalyst due to a lack of knowledge about the material, its structure and composition. As a result, most synthesis processes yield low surface area molybdenum carbide with contaminants such as excess carbon. In this study reported herein, we carried out DFT assisted thermodynamic modeling to better understand molybdenum carbon phase behavior. Our gas phase equilibrium studies led to better comprehension and refinement of synthesis parameters and conditions. With the help of these thermochemical models, we were able to design a decarburization via hydrogen methanization treatment that yielded 2 nm MoC particles free of contaminants with the highest surface areas reported so far i.e. up to 360 m²/g.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC)
• Sponsoring Organization: USDOE Advanced Research Projects Agency - Energy (ARPA-E); USDOE National Nuclear Security Administration (NNSA); USDOE Office of Science (SC), Advanced Scientific Computing Research (ASCR)
• Grant/Contract Number: 89233218CNA000001; AC02-05CH11231
• OSTI ID: 1597340
• Alternate ID(s): OSTI ID: 1504781
• Report Number(s): LA-UR-19-20519
• Journal Information: Thermochimica Acta, Vol. 676, Issue C; ISSN 0040-6031
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
Molybdenum carbide
Ellingham diagrams
Decarburization via methanization
Gas phase equilibrium studies
Phonon thermal properties calculations