The influence of supported Ni catalysts on the product gas distribution and H2 yield during cellulose pyrolysis

Two groups of Ni catalysts, supported on gamma-Al2O3 and MCM-41, respectively, were prepared by incipient wetness impregnation and tested for their influence on the pyrolytic decomposition of cellulose. A thermogravimetric analyser coupled with a mass spectrometer (TG-MS) was used to examine the influence of catalyst loading, support material, and the presence of additional water vapour on H-2 selectivity. Normalization of the raw MS data enabled semi-quantitative analysis of the product gas distribution, which facilitated reliable comparison between different experimental conditions. Catalysts were characterized by BET, XRD, SEM/EDX and TEM. MCM-41 supported Ni significantly elevated the yield of H2 and total gaseous product, both under Ar and with the injection of additional water vapour when compared with the gamma-Al2O3 support. 15 wt.%Ni/-y-Al2O3 and 5 wt.%Ni/MCM-41 were identified as the most active catalysts from the two groups with regards to H-2 selectivity and yield. (C) 2009 Elsevier B.V. All rights reserved.