Insights into reduction of CO₂ to CO catalyzed by pyramidal-4Ni clusters supported on doped CeO₂(111)

Converting CO₂ into valuable chemicals has become a widely used research method for CO₂ conversion. In this work, the catalytic performance of pyramidal-4Ni catalysts supported on rare earth metal-doped CeO₂ toward CO₂ reduction reaction (CO₂RR) was investigated by using density-functional theory calculations. For rare earth metal-doped CeO₂, 2Ce is substituted by 2 trivalent cations and at the same time one oxygen vacancy is created to make charge compensation. We investigated the oxygen vacancy nearest (V_O,N) and next-nearest (V_O,NN) to 4Ni, and found releasing CO and CO₂ dissociation are the rate-determining steps, respectively, via the path of V_O,N and V_O,NN. Among the studied dopants (Ga, Sb, Lu, Gd, Pr, La, Bi), Gd is identified as the best dopant for catalyzing the reduction of CO₂ at 823 K, with the turn-over frequency (TOF) of 10⁴ times as large as that over 4Ni supported on pure CeO₂. This exploration pro-vides theoretical support and guidance for the research and application of rare earth metaldoped CeO₂-loaded Ni catalysts in the field of CO₂ reduction.