Effects of Metal Promotion on the Performance of CuZnAl Catalysts for Alcohol Synthesis

A series of CuZnAl catalysts modified with different promoters (Fe, Co, Ru, Zr, Mo, Mg, Mn, and Cr) have been prepared through co-precipitation, characterised by applying a combination of techniques, and tested for carbon monoxide hydrogenation. Cu reducibility in CuZnAl catalysts was affected by the addition of promoters. The ease of Cu reduction in the promoted catalysts leads to more active catalysts for the hydrogenation of carbon monoxide and the production of C2+ alcohols, whereas lower catalytic activity was observed over less reducible catalysts. The promotion of CuZnAl catalysts even with small amounts of Cr, Mn, and Fe resulted in a significant modification in the reaction selectivity. The Fe-containing catalyst demonstrated a dramatic increase in carbon monoxide conversion and C2+ alcohol productivity (30 mg g h−1).