Electrodeposited Cu-ZnO and Mn-Cu-ZnO nanowire/tube catalysts for higher alcohols from syngas

Cu-ZnO and Mn-Cu-ZnO catalysts have been prepared by electrodeposition and tested for the synthesis of higher alcohols via CO hydrogenation. The catalysts were prepared in the form of nanowires and nanotubes using a nanoporous polycarbonate membrane, which served as a template for the electrodeposition of the precursor metals from an aqueous electrolyte solution. Electrodeposition was carried out using variable amounts of Zn(NO3)(2), Cu(NO3)(2), Mn(NO3)(2) and NH4NO3 at different galvanostatic conditions. A fixed bed reactor was used to study the reaction of CO and H-2 to produce alcohols at 270 degrees C, 10-20 bar, H-2/CO = 2/1, and 10,000-33,000 scc/h g(cat). In addition to methane and CO2, methanol was the main alcohol product. The addition of manganese to the Cu-ZnO catalyst increased the selectivity toward higher alcohols by reducing methane formation; however, CO2 selectivity remained high. Maximum ethanol selectivity was 5.5%, measured as carbon efficiency. (C) 2009 Elsevier B.V. All rights reserved.