Graphitic mesoporous carbon as a support of promoted Rh catalysts for hydrogenation of carbon monoxide to ethanol

Graphitic mesoporous carbon (GMC), prepared through high-temperature graphitization of soft-templated amorphous mesoporous carbon (AMC), was used as the support for Mn, Li, and Fe triple-promoted Rh catalysts for CO hydrogenation to ethanol. The use of GMC results in C2H5OH selectivity and formation rate comparable to nonporous SiO2 support along with a significant inhibition on the formation of undesired CH4 and light hydrocarbons at the expense of appreciable amounts of CO2 produced. The better catalytic performance of promoted-Rh/GMC than those supported on other carbon allotropes (AMC and non-porous graphitic carbon black) seems to be associated with the specific graphitic structure and mesoporosity of GMC. The surface modification of GMC by wet oxidation leads to considerable increases in C2H5OH selectivity and formation rate. The modified GMC as a support shows substantially greater CO2-free selectivity for C2H5OH than the SiO2.