Activity-enhanced copper-zinc based catalysts for the hydrogenolysis of esters

摘要: Abstract For silica-supported copper-zinc catalysts, a fivefold enhancement of the activity in hydrogenolysis methyl acetate has been obtained by high-temperature reductions range between 550 K and 700 K. Furthermore, simultaneously, selectivity was significantly improved. At equal conversion acetate, catalysts reduced at high temperature make less side products than low temperature. The selectivities to methane ethane as function reduction indicate that these are formed on copper metal sites. formation ethene most likely proceeds dehydration ethanol acid presence crystallites 3–5 nm absence crystalline zinc oxide were established X-ray diffraction. increase is ascribed additional highly active sites interaction with zinc-containing phase. Fourier-transform infrared spectroscopy adsorbed carbon monoxide confirmed metallic more important oxidized copper. Reduction 750 results brass catalyst deactivation evaporation zinc. enhanced can be preserved passivation therefore relevant practical applications. After prolonged exposure air original restored low-temperature reduction.