Influence of the support on the catalytic behaviour of Ni catalysts for the dry reforming reaction and the tri-reforming process

Abstract

The influence of different support materials (alumina, ceria, β-silicon carbide and yttria-stabilized zirconia) on the catalytic behaviour of Ni catalysts for the dry reforming reaction and the tri-reforming process has been studied. The influence on the catalytic performance of the composition of the atmosphere surrounding the Ni/YSZ catalyst during the calcination step was also analysed. Temperature-programmed reduction experiments showed remarkable differences in the reduction profile and the degree of reduction of the catalysts as a function of both the support used and the calcination conditions. Ni/YSZ-O2, the catalyst calcined under an oxygen-poor atmosphere, presented a higher reducibility as a consequence of the higher number of oxygen vacancies in the surface of the support. The Ni/Al2O3 catalyst gave the lowest CH4 and CO2 reaction rates as a consequence of its low reducibility due to the formation of Ni aluminate. The Ni/CeO2 catalyst showed the lowest H2/CO molar ratio for the tri-reforming process. This result can be explained on considering the higher basicity of this catalyst, as shown by CO2-TPD experiments. The CeO2 and β-SiC catalysts had the best characteristics as catalytic supports for the tri-reforming process.