Dispersed Nickel Boosts Catalysis by Copper in CO2 Hydrogenation

The empirical optimization of the preparation of catalytically active copper-containing catalysts is far more advanced than the fundamental understanding of the catalyst performance because of the structural complexity of the catalysts. Here, we demonstrate the interplay between the catalyst structure and CO2 hydrogenation on Cu catalysts boosted with nickel species. The nickel dispersion on copper markedly affects the CO2 dissociation activity and catalytic reaction pathways, thus resulting in distinctive catalytic activity and selectivity attributed to Ni. Specifically, the catalyst incorporating nickel alloyed in copper maximizes the synergy between the two metals and is characterized by conversions close to the thermodynamic equilibrium to CO as a product—with switched off methanation—over a wide temperature range. Catalyst performance data, spectra characterizing the catalyst, and theoretical results demonstrate that surface copper with adjacent nickel atoms efficiently activates CO2 via a redox mechanism—with adsorption of CO being suppressed—so that methanation associated with deep hydrogenation of CO is inhibited. The results of this investigation highlight the importance of structures with copper-adjacent-nickel, which appear to offer appealing opportunities for tailoring efficient copper-containing catalysts for CO2 hydrogenation.