Structural Evolution of Molybdenum Carbides in Hot Aqueous Environments and Impact on Low-Temperature Hydroprocessing of Acetic Acid

Catalysts

Jae-Soon Choi²  Viviane Schwartz²  Eduardo Santillan-Jimenez¹  Mark Crocker¹  Samuel A. Lewis²  Michael J. Lance²  Harry M. Meyer²  Karren L. More² 

[1] University of Kentucky Center for Applied Energy Research, 2540 Research Park Drive, Lexington KY 40511, USA; E-Mails:;Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831, USA; E-Mails:

关键词: molybdenum carbide;    Mo₂C;    biomass;    bio-oil;    pyrolysis oil;    hydroprocessing;    acetic acid hydrogenation;    heterogeneous catalysis;   

DOI  :  10.3390/catal5010406

来源: mdpi

【 摘 要 】

We investigated the structural evolution of molybdenum carbides subjected to hot aqueous environments and their catalytic performance in low-temperature hydroprocessing of acetic acid. While bulk structures of Mo carbides were maintained after aging in hot liquid water, a portion of carbidic Mo sites were converted to oxidic sites. Water aging also induced changes to the non-carbidic carbon deposited during carbide synthesis and increased surface roughness, which in turn affected carbide pore volume and surface area. The extent of these structural changes was sensitive to the initial carbide structure and was lower under actual hydroprocessing conditions indicating the possibility of further improving the hydrothermal stability of Mo carbides by optimizing catalyst structure and operating conditions. Mo carbides were active in acetic acid conversion in the presence of liquid water, their activity being comparable to that of Ru/C. The results suggest that effective and inexpensive bio-oil hydroprocessing catalysts could be designed based on Mo carbides, although a more detailed understanding of the structure-performance relationships is needed, especially in upgrading of more complex reaction mixtures or real bio-oils.

【 授权许可】

CC BY   
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