Synthesis, characterization and activity of Co and Ni catalysts supported on AlMe (Me = Zn, Zr, Ti) mixed oxides

Abstract

Binary Al-Ti, Al-Zr and Al-Zn oxides, prepared by the sol-gel method were used as supports of catalytic systems. The catalysts were prepared by impregnation of these supports with the low cost Co or Ni nitrate salts and subsequent calcination at 700 C. Catalysts have been characterized by S BET, XRD and TPR techniques. The catalysts were tested in ethanol partial oxidation using a fixed-bed quartz reactor at atmospheric pressure and temperature at 600 C. In test reactions a constant feed composition was used with O2/EtOH molar ratio of 0.75 in nitrogen balance. The catalytic performance of the systems depends on type of support and type of promoter. Hydrogen and CO are the predominant products beside some by-products in different quantities (CO2, methane, ethylene, acetaldehyde, acetone, acetic acid). The Co and Ni catalysts supported on AlZn binary oxide showed the highest selectivity to hydrogen and to carbon monoxide with full ethanol conversion. Selectivity of hydrogen follows the order of Co(Ni)AlZn > Co(Ni)AlTi > Co(Ni)AlZr. The best performance was obtained by NiAlZn catalyst with 89 % hydrogen selectivity. © 2012 The Author(s).