Abstract: A K-Co-Mo-C catalyst with remnant carbon was prepared by the sol-gel method. The carbon content was adjusted by adding different amounts of carbon precursor. Catalytic behavior of mixed alcohols synthesis from syngas was investigated over the catalysts. By combining different characterization techniques, such as X-ray diffraction, thermo-gravimetric analysis, N2 adsorption isotherms method, and temperature-programmed desorption of hydrogen, it was revealed that the presence of appropriate content of remnant carbon increased the dispersion of active phase and improved the yield and selectivity for alcohol. For the catalysts with superfluous remnant carbon, the selectivity for alcohol decreased and the selectivity for hydrocarbon increased, which might be due to the fact that with the increase of amount of carbon precursors, Mo species was readily reduced to the metallic state. For the sample calcined in air, the metal oxide precursors were easily aggregated to irreducible compound, so the activity for alcohol synthesis was low. The sample with 2.8% carbon had the largest surface area and pore volume, and showed the highest activity for alcohol synthesis. Calcining sample at higher temperature in inert atmosphere also caused the activity for alcohol synthesis to decrease obviously, but the selectivity for C2+ alcohols increased markedly.

Key words: potassium, cobalt, molybdenum, carbon, syngas, mixed alcohol