CO₂ and CO hydrogenation over Ni-supported materials

Abstract

This work reports on the fundamental properties of nanostructured catalysts active in the main carbon oxides’ conversion processes for sustainable energy supply: methanation and co-methanation of CO 2 . Transition metals (e.g. Ni, Pd, Pt, Co, Ru, Rh) are active species in both reactions. Ni has been the most studied because of its cheapness. Monometallic and bi-metallic Ni and Ni 3 Fe catalysts supported on Gadolinia-doped ceria (GDC) have been synthesized, characterized and tested in the temperature range 200–600[Formula: see text]C. In the methanation reaction, the monometallic catalyst showed higher performance with respect to the bi-metallic catalyst. At 400[Formula: see text]C, the CO 2 conversion overcomes 90% with CH 4 selectivity of 100%. In co-methanation, the highest CO 2 , CO and H 2 conversion values over monometallic Ni/GDC catalyst were obtained at 300[Formula: see text]C; at higher temperatures, conversion decreases. The GDC support plays a pivotal role in both reactions, enhancing the basicity of the catalyst and improving the dissociation of carbon oxide species adsorbed on Ni sites.