Activated Carbon, Carbon Nanofiber and Carbon Nanotube Supported Molybdenum Carbide Catalysts for the Hydrodeoxygenation of Guaiacol

Catalysts

Eduardo Santillan-Jimenez²  Maxime Perdu²  Robert Pace²  Tonya Morgan²  Mark Crocker¹ 

[1]University of Kentucky Center for Applied Energy Research, 2540 Research Park Drive, Lexington, KY 40511, USA

关键词: activated carbon;    carbon nanofibers;    carbon nanotubes;    molybdenum;    carbide catalysts;    hydrodeoxygenation;    guaiacol;    bio-oil upgrading;   

DOI  :  10.3390/catal5010424

来源: mdpi

【 摘 要 】

Molybdenum carbide was supported on three types of carbon support—activated carbon; multi-walled carbon nanotubes; and carbon nanofibers—using ammonium molybdate and molybdic acid as Mo precursors. The use of activated carbon as support afforded an X-ray amorphous Mo phase, whereas crystalline molybdenum carbide phases were obtained on carbon nanofibers and, in some cases, on carbon nanotubes. When the resulting catalysts were tested in the hydrodeoxygenation (HDO) of guaiacol in dodecane, catechol and phenol were obtained as the main products, although in some instances significant amounts of cyclohexane were produced. The observation of catechol in all reaction mixtures suggests that guaiacol was converted into phenol via sequential demethylation and HDO, although the simultaneous occurrence of a direct demethoxylation pathway cannot be discounted. Catalysts based on carbon nanofibers generally afforded the highest yields of phenol; notably, the only crystalline phase detected in these samples was Mo₂C or Mo₂C-ζ, suggesting that crystalline Mo₂C is particularly selective to phenol. At 350 °C, carbon nanofiber supported Mo₂C afforded near quantitative guaiacol conversion, the selectivity to phenol approaching 50%. When guaiacol HDO was performed in the presence of acetic acid and furfural, guaiacol conversion decreased, although the selectivity to both catechol and phenol was increased.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.