Synthesis of Ethanol via Syngas on Cu/SiO_2 Catalysts with Balanced Cu°-Cu~+ Sites

摘要

This paper describes an emerging synthetic route for the production of ethanol (with a yield of ~83%) via syngas using Cu/SiO_2 catalysts. The remarkable stability and efficiency of the catalysts are ascribed to the unique lamellar structure and the cooperative effect between surface Cu~0 and Cu~+ obtained by an ammonia evaporation hydrothermal method. Characterization results indicated that the Cu~0 and Cu~+ were formed during the reduction process, originating from well-dispersed CuO and copper phyllosilicate, respectively. A correlation between the catalytic activity and the Cu~0 and Cu~+ site densities suggested that Cu~0 could be the sole active site and primarily responsible for the activity of the catalyst. Moreover, we have shown that the selectivity for ethanol or ethylene glycol can be tuned simply by regulating the reaction temperature.