Nanoporous Platinum/(Mn,Al)<sub>3</sub>O<sub>4</sub> Nanosheet Nanocomposites with Synergistically Enhanced Ultrahigh Oxygen Reduction Activity and Excellent Methanol Tolerance

At present, metal/metal oxide composites are considered as potential oxygen reduction reaction (ORR) catalysts for energy-related applications like fuel cells. Here, we fabricated a high-activity, low Pt loading ORR electrocatalyst composed of nanoporous Pt (np-Pt) in intimate contact with lamellar (Mn,Al)<sub>3</sub>O<sub>4</sub> nanosheet (NS). In comparison to Pt/C (Johnson Matthey), the np-Pt/(Mn,Al)<sub>3</sub>O<sub>4</sub> NS catalyst shows a 11.5-fold enhancement in the mass-normalized ORR activity and much better methanol tolerance because of the metal–support interactions between np-Pt and (Mn,Al)<sub>3</sub>O<sub>4</sub>. Furthermore, the combination of electrochemical experiments with theoretical calculations verifies that the ORR on the np-Pt/(Mn,Al)<sub>3</sub>O<sub>4</sub> NS catalyst is a direct 4e<sup>–</sup> pathway in the alkaline solution. In addition, the electrocatalytic mechanisms have also been rationalized by density functional theory (DFT) calculations.