Highly Selective Copper Catalyst Supported on Mesoporous Carbon for the Dehydrogenation of Ethanol to Acetaldehyde

The dehydrogenation of ethanol to acetaldehyde is of great importance in synthetic chemistry and the fine chemical industry. In this study, we report that a mesoporous-carbon-supported Cu catalyst exhibited a high reaction rate and excellent product selectivity in ethanol dehydrogenation to acetaldehyde. Under the severe conditions of an ethanol concentration of 15vol% and a gaseous hourly space velocity of 8600h(-1), the Cu-based carbon catalyst maintains a conversion of approximate to 73% and an acetaldehyde selectivity of approximate to 94% at 553K. Meanwhile, a prominent space time yield (225h(-1)) of acetaldehyde is obtained, which is far higher than that (112h(-1)) on the mesoporous-SBA-15-supported Cu catalyst. Ethanol adsorption studies prove that the enrichment of the carbon support for reactants makes a contribution to the high reaction rate. Importantly, kinetic measurements indicate that the scarce surface groups of the mesoporous carbon support minimize the secondary reactions of acetaldehyde, which are generally catalyzed by OH and/or COOH on the surface of the support as exemplified by the mesoporous-SBA-15-supported Cu catalyst. This accounts for the excellent selectivity toward acetaldehyde on the mesoporous-carbon-supported Cu catalyst. Therefore, these surface characteristics of the carbon support show great advantages in this dehydrogenation reaction.