Highly efficient nickel-niobia composite catalysts for hydrogenation of CO₂ to methane

We studied the catalytic hydrogenation of CO₂ to methane using nickel-niobia composite catalysts. Catalysts containing 10–70 wt% Ni were synthesized by wet impregnation and tested for CO₂ hydrogenation in a flow reactor. 40 wt% was found to be the optimum Ni loading, which resulted in CO₂ conversion of 81% at 325 °C. We also calcined the Nb₂O₅ support at different temperatures to study the influence of calcination temperature on the catalytic performance. 40 wt% Ni loaded on Nb₂O₅, which was calcined at 700 °C gave higher methanation activity (91% conversion of CO2). Time on stream study for 50 h showed a stable activity and selectivity; thus confirming the scope for practical application.