Accelerating CO2 Electroreduction to CO Over Pd Single‐Atom Catalyst.

The electrochemical conversion of carbon dioxide (CO2) into value‐added chemicals is regarded as one of the promising routes to mitigate CO2 emission. A nitrogen‐doped carbon‐supported palladium (Pd) single‐atom catalyst that can catalyze CO2 into CO with far higher mass activity than its Pd nanoparticle counterpart, for example, 373.0 and 28.5 mA mg−1Pd, respectively, at −0.8 V versus reversible hydrogen electrode, is reported. A combination of in situ X‐ray characterization and density functional theory (DFT) calculation reveals that the PdN4 site is the most likely active center for CO production without the formation of palladium hydride (PdH), which is essential for typical Pd nanoparticle catalysts. Furthermore, the well‐dispersed PdN4 single‐atom site facilitates the stabilization of the adsorbed CO2 intermediate, thereby enhancing electrocatalytic CO2 reduction capability at low overpotentials. This work provides important insights into the structure‐activity relationship for single‐atom based electrocatalysts. [ABSTRACT FROM AUTHOR]