Enhancement of catalytic activity in CO2 methanation in Ni-based catalysts supported on delaminated ITQ-6 zeolite

Ni-based catalysts supported on delaminated ITQ-6 zeolite with different Si/Al ratios, 30 and infinity, were tested in the methanation of CO2 and CO. ITQ-6 supports exhibited high surface areas (> 590 m(2)/g), and the catalysts based on them presented elevated CO2 and CO conversion values, turnover frequencies (TOF), and CH4 selectivity (> 90 %). Comparing the ITQ-6 catalyst and its precursor ferrierite (FER)-based catalyst, H-2-chemisorption results confirmed higher metallic dispersion for the former, which resulted in improved H-2 uptake and efficient interaction of reaction intermediates via the associative pathway. Combined kinetic studies indicated that their higher available metallic surface contributed to lower apparent activation energies towards CH4 formation, accounting for the higher selectivity values. A 15 wt% Ni-based catalyst supported on ITQ-6 zeolite (Si/Al = 30) exhibited catalytic results (X-CO2 = 79 % y S-CH4 = 98 %) comparable or even superior to some of the best zeolite-based catalysts reported so far.