Effect of elemental molar ratio on the synthesis of higher alcohols over Co-promoted alkali-modified Mo2C catalysts supported on CNTs

A series of molybdenum carbide catalysts promoted by potassium and cobalt, supported on carbon nanotubes (CNTs) were prepared by carbothermal hydrogen reduction method using CNTs as a carbon precursor. Firstly, molybdenum and cobalt were loaded by co-precipitation method, and then potassium and additional molybdenum were impregnated to previous resultant. Different Mo/Co and K/Co molar ratio were used in catalyst synthesis. All the catalysts were characterized by ICP, BET, TEM, TPR, XRD and XPS, and the catalysts performances for higher alcohols synthesis (HAS) were investigated in a fixed-bed micro-reactor. The maximum selectivity to higher alcohols (C2+OH) was obtained at Mo/Co and K/Mo molar ratios of 1.66 and 0.6, respectively. XRD results confirmed the formation of K-Mo-C site and Co3Mo3C phase that might play important role in producing C2+OH.

Addition and increasing potassium to Mo-Co/MWCNT with Mo/Co=1.66 molar ratio made the process more selective for production of higher alcohols. However, the increasing in the K/Co ratio decreased CO conversion but it was not significant.Figure optionsDownload full-size imageDownload as PowerPoint slide