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 CeZrO 2 –Al 2 O 3 support compositions. Catalysts with a higher CeZrO 2 /Al 2 O 3 ratio exhibited greater CH 4 and CO 2 conversions and higher H 2 /CH 4 yields, while displaying lower H 2 /CO ratios and reduced coke formation. Catalytic stability tests over 200 h showed CH 4 and CO 2 conversion rates of 93–97% and 0–5%, respectively. CeZrO 2 -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 CeZrO 2 /Al 2 O 3 ratio of the catalyst support.