Atomically Dispersed CrOX on Pd Metallene for CO-Resistant Methanol Oxidation.

The effective design and construction of high-performance methanol oxidation reaction (MOR) electrocatalysts are significant for the development of direct methanol fuel cells. But the active sites of the MOR electrocatalysts are susceptible to being poisoned by CO, resulting in poor durability. Herein, we report an atomically dispersed CrOX species anchored on Pd metallene through bridging O atoms. This catalyst shows an outstanding MOR performance with 7 times higher mass activity and 100 mV lower CO electrooxidation potential than commercial Pd/C. The results of operando electrochemical Fourier transform infrared spectroscopy demonstrate the rapid removal of CO* on CrOX-Pd metallene. Theoretical calculations reveal that atomically dispersed CrOX can lower the adsorption energy of CO* on Pd sites and enhance that of OH* through the formation of a hydrogen bond, decreasing the formation energy of COOH*. This work provides a new strategy for improving MOR performance via atomically engineering oxide/metal interfaces.