Phosphorus-Induced Dual-Sites and High-Index PtCu (3 1 1) crystal planes for modifying oxygen reduction pathway

Abstract

The oxygen reduction reaction (ORR) on Pt-based catalysts is largely retarded by the stronger adsorption of the intermediates on Pt (111) than ideal catalysts. Synergistic catalysis offers a promising approach to reshape the electronic structure of the designed catalyst for optimizing the adsorption energy of the intermediates on its surface. Herein, we certificate that the intermediates adsorption on the C-supported PtCu alloy catalyst can be modulated synergistically by distorted PtCu (111) crystal planes and P-C sites caused by P-doping, leading to a substantial increase in ORR. In situ spectral evidence of two *OOH intermediates on the above dual sites identifies the role of introduced metalloid P elements in promoting the ORR association pathway. Notably, the high-index PtCu (311) crystal planes of the P-doped catalysts have shown a distinct enhancement with abundant terraces and step densities, which contributes to the highest ORR activity of PtCu/PC-3 with the mass activity (MA) of 0.82 A mgPt-1 (0.8 V). Analysis of the *OH real-time adsorption behaviors on this crystal plane suggests that another parallel dissociation pathway is also in operation. Benefiting from the increased active site species and the enhanced intrinsic activity, the optimal PtCu/PC-3 also exhibits the impressive performance in methanol oxidation reaction (MOR).