A novel catalyst for direct vapor phase carbonylation of ethanol
Chemical Journal of Chinese Universities, 21(9), pp 1462-1464, 2000-9
A novel Mo/C catalyst, which are reduced in H-2 after sulfidizaing ammonium heptamolybdate with (NH4)(2)S aqueous solution, has a high activity and selectivity for ethanol vapor phase carbonylation to ethyl propionate without addition of any promoter in the feed. Ethanol carbonylation is carried out in a fixed bed reactor with a continuous flow system at atmospheric pressure. This catalyst has a higher initial activity and selectivity; the catalytic activity reaches steady state after carbonylation reaction for 30 min. Higher temperatures led to a sharp decrease of the carbonylation activity and to an increase of the selectivities of ethene and ether. The optimal reaction conditions are as follows: reaction temperature is 553 K; n(C2H5OH)/n(CO) = 4/1; GHSV = 4.0 L/(g cat . h). Under these conditions, the conversion of ethanol is 80%, the selectivity of ethyl propionate is 80.6% and the space-time yield is 1.157 x 10(-2) mol/(g cat . h). This result is surprisingly better than that of ethanol vapor phase carbonylation over Ni-Zn/C catalyst with addition of ethyl iodide promoter to the feed [n(C2H5OH)/n(C2H5I) = 10/1], especially, this novel Mo/C catalyst has a significantly higher selectivity. No carbonylation product is found over Ni base catalyst without addition of the promoter. This research demonstrates that novel Mo/C catalyst may be promising for ethyl propionate production from the carbonylation of ethanol at atmospheric pressure, without requiring ethyl iodide as promoter. This novel catalyst is found to be a non-crystalline by X-ray diffraction. The Mo content in the catalyst is 10%.
ethanol; vapor phase carbonylation; supported catalyst; ethyl propionate; carbonylation