A density functional theory-guided discovery of bimetallic transition-metal-doped cerium oxide catalysts for the reverse water gas shift reaction

Reverse water–gas shift (RWGS) reaction is a promising route for CO 2 utilization and syngas production, yet its efficiency remains limited by catalyst performance. This study performed density-functional-theory-calculations to systematically investigate bimetallic transition-metal (TM)-doped CeO 2 (111) catalysts (M 1 M 2 /CeO 2−x ; M 1 = Fe; M 2 =Cu/Ni/Co/Mn) for direct CO 2 -to-CO reduction. A comprehensive configurational search of dopant distributions, oxygen-vacancy (OV) sites, CO 2 adsorption and dissociation configurations identified representative configurational reaction pathways: PW1 (most-stable), PW2 (most-likely), and PW3 (most-reactive), collectively mapping the full reaction energy landscape. Reaction energies (E rxn ) were used as performance descriptors based on their linear Brønsted-Evans-Polanyi (BEP) relationship with activation energies. Among all bimetallic candidates, FeCo/CeO 2−x shows the best performance, exhibiting the lowest E rxn for PW1 & PW2 and the 2nd-lowest for PW3 , outperforming the benchmark 2Fe/CeO 2−x except for a minor shortfall in PW2 . FeNi/CeO 2−x catalyst is the 2nd-best, achieving the lowest E rxn in PW3 . Both catalysts display spontaneous adsorption of CO and O after CO 2 dissociation. Transition-state analysis reveals a precursor-mediated direct CO 2 -reduction pathway and confirms linear-BEP relationships. Local dopant-environment and electronic-structure analysis reveal synergistic interactions among CeO 2 , bimetallic-dopants, and OV modulate CeO 2 -reducibility and OV-stability, tailor CO 2 adsorption and dissociative-adsorption modes, thereby tuning overall surface reactivity. These findings highlight FeCo/CeO 2−x and FeNi/CeO 2−x as promising next-generation RWGS catalysts.