Rare earth praseodymium-based single atom catalyst for high performance CO2 reduction reaction

• Praseodymium-based single-atom catalyst was designed and synthesized. • This kind of catalyst exhibits excellent catalytic performance for the electrochemical CO 2 reduction reaction. • The reaction mechanism has been revealed by DFT calculations. Rare earth single-atom catalysts (SACs) can be used to obtain atomically dispersed species on supports to provide the maximum number of well-defined active sites, which would subsequently maximize the utilization of rare earth metals. However, the design and synthesis of SACs are mostly based on transition metals, and rare earth SACs have been rarely explored. Herein, we report a rare earth praseodymium SAC dispersed on a porous carbon substrate by utilizing the cascade anchoring strategy, with a metal loading of up to 5.07 wt%. This praseodymium SAC exhibits excellent catalytic performance for the electrochemical CO 2 reduction reaction (CO 2 RR) and achieves high selectivity for CO, with a faradaic efficiency (FE CO ) of up to 93% at a low potential of −0.43 V vs RHE. Experiments and theoretical calculations confirm that the isolated praseodymium atoms on the substrate are critical for improving the CO 2 RR performance of the material.