Effects of CeZrO2–Al2O3 support composition of metal-foam-coated Pd–Rh catalysts for the steam-biogas reforming reaction

Abstract

Biogas conversion to syngas by steam reforming was studied over metal-foam-coated Pd–Rh catalysts with variable CeZrO2–Al2O3 support compositions. Catalysts with a higher CeZrO2/Al2O3 ratio exhibited greater CH4 and CO2 conversions and higher H2/CH4 yields, while displaying lower H2/CO ratios and reduced coke formation. Catalytic stability tests over 200h showed CH4 and CO2 conversion rates of 93–97% and 0–5%, respectively. CeZrO2-modification of the catalyst leads to reduction in the BET area and metal dispersion. Sintering was observed in used catalysts; however there was no clear correlation between the extent of morphological deterioration and the CeZrO2/Al2O3 ratio of the catalyst support.