Steam reforming of ethanol over copper-zirconia based catalysts doped with Mn, Ni, Ga

The activity toward hydrogen production in steam reforming of ethanol (SRE) reaction has been evaluated for CuO/ZrO2 catalysts doped with Mn, Ni, Ga at 350 degrees C. The copper based catalysts were synthesised by co-precipitation method at constant pH = 7 and fixed (wt.%) CuO/ZrO = 2.3. The catalysts were characterised by means of N-2 adsorption, temperature programmed reduction (H-2-TPR), N2O dissociative chemisorption, X-ray diffraction (XRD), CO2 temperature programmed desorption (CO2-TPD), and temperature programmed oxidation (TPO). It has been found that copper based catalysts exhibit high ethanol conversion in SRE (>86%) at 350 degrees C. Due to basic character of catalysts, the formation of acetaldehyde is observed. The CuO/ZrO2 catalyst modification with dopants increases the hydrogen yield with maximum (52%) for CuO/ZrO2/NiO. The addition of Ni changes the distribution of carbon-containing products. In this case, the increase in selectivity to CO, CO2 and CH4 is observed whereas selectivity to acetaldehyde is significantly decreased. This shows that presence of Ni facilities the C-C bond cleavage. On the other hand, the formation of acetic acid is limited upon addition of Mn and Ga. For all modified catalysts, decrease in carbon deposition rate during SRE is pronounced according to TPO experiments. The modification of Cu/Zr with Mn, Ni and Ga causes the decrease in copper particle size, which hinders the carbon deposit formation. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.