Abstract: Ni/γ-Al2O3 catalysts modified by La2O3 were prepared with incipient wetness impregnation and used in biogas reforming to hydrogen. The catalysts were characterized with XRD, H2-TPR, BET, and TEM, respectively, and the relationship between the performance and the structural properties of the catalysts was investigated. The biogas was simulated with CH4 and CO2, and the volume ratio of CH4/CO2 was 1. The results showed that the amount of La2O3 added was a key influence factor. The increment of La2O3 in γ-Al2O3 support strengthened the interaction between Ni and γ-Al2O3. Appropriate accession of La2O3 could improve the reducibility of catalysts, increase the dispersity of metallic Ni on support, suppress the sintering of metallic Ni particles and enhance the adsorption of CO2 on support during the reaction. As a result, the performance of catalyst, including resistance to coking, activity and stability, was improved significantly. However, excessive addition of La2O3 deteriorated the performance of catalyst. It was found that the best performance of catalyst could be reached at the addition of 6% (w) La2O3 in γ-Al2O3.

Key words: Lanthanumoxide, Nickel, Alumina, Biogas reforming, Hydrogen production, Dispersity, Resistance to coking