Strain Engineering to Enhance the Oxidation Reduction Reaction Performance of Atomic-Layer Pt on Nanoporous Gold

Developing efficient and durable but low Pt loading catalysts for the oxygen reduction reaction (ORR) is essential for commercialization of proton-exchange membrane fuel cells. According to Pt-based ORR catalysts, the compressive lattice of Pt which will reduce the d-band center is beneficial to improve ORR activity. Au has been recognized as an effective stabilizing element to increase the durability of Pt electrocatalysts for the ORR. In this paper, nanoporous gold (NPG) films with compressive lattice parameters were used as the substrate to engineer the surface strains of the coated monolayer Pt (NPG-Pt). Then, the effects of surface strain of these NPG-Pt catalysts on ORR activity were investigated in detail. The experimental results indicate that the lattice constant of Pt reduces ∼1.8%, and the intrinsic ORR activity increases about three times. Furthermore, the intrinsic and mass ORR activity of the NPG-1.8%-Pt sample is about 5 and 16 times higher than that of the commercial Pt/C catalyst. After 10 k cycles of durability tests, the intrinsic and mass ORR activity of NPG-Pt decreased ∼1.8%, which is obviously lower than that of Pt/C (35%).