Tuning the ORR activity of Pt-based Ti2CO2 MXene by varying the atomic cluster size and doping foreign metals
The rational design of ideal catalysts for the oxygen reduction reaction (ORR) is of great significance for solving the electrocatalytic potential problems in proton exchange membrane fuel cells (PEMFCs). The Ptn (n = 1-4) and Pt3Au alloy subnanoclusters supported on the defective Ti2CO2 monolayer with oxygen vacancy (denoted as v-Ti2CO2) are simulated by using density function theory to investigate their ORR performance. The geometries, energetics, and electronic properties of the different systems are analyzed. It is found that the supported Pt3Au alloy subnanocluster possesses the best ORR activity. The underlying mechanisms of the improved ORR activity originated from the moderate hybridization between the O 2p and the 5d orbitals of Au and Pt according to the density of states analysis. Our study provides a facile route for designing low-cost MXene-based electrocatalysts by alloying transition metal with the Pt catalyst, which may stimulate realization of suitable alternative catalysts for ORR catalysis.