Novel Pulse Electrodeposited Co–Cu–ZnO Nanowire/tube Catalysts for C1–C4 Alcohols and C2–C6 (Except C5) Hydrocarbons from CO and H2

Abstract

Co−Cu−ZnO nanowire/tube catalysts were synthesized using pulse electrodeposition technique from a single aqueous electrolyte solution using a template synthesis technique. They were then tested as catalysts for the hydrogenation of CO to alcohols and higher hydrocarbons. Nanowires/ tubes were grown inside the pores of membranes using a three-step sequential deposition process. First, a low current of−6.9 mA/cm2 was applied for 300 ms for Cu deposition, then a high current density of −11.5 mA/cm2 for t ms (t = 500, 600, 750 ms) was applied for Co deposition, and finally no current was applied for 1200 ms so that the ions near the cathode replenish. The surface had a significantly different composition than the bulk. On the surface, there was more Co, less Cu, and more Zn. The catalyst showed the alcohol (C1−C4) selectivity of 20.9 %C at H2/CO = 3/1, GHSV = 16 000 scc/h gcat, temperature = 270 °C, pressure = 15 bar, and time-onstream = 65 h.