Thermally Robust Porous Bimetallic (Ni xPt1- x) Alloy Mesocrystals within Carbon Framework: High-Performance Catalysts for Oxygen Reduction and Hydrogenation Reactions.

Abstract

Thermally stable porous bimetallic (Ni xPt1- x) alloy mesocrystals within a carbon framework are produced via an aerosol-assisted process for high-performance catalysts for the oxygen reduction reaction (ORR) and hydrogenation. The porous Ni xPt1- x alloy has a robust composite of alloy nanoparticles with an adjustable composition and a porous carbon skeleton. Porous Ni xPt1- x alloys exhibit high thermal stability, retaining their crystalline structure and morphology at 550 °C for 6 h, as observed in thermal treatment tests under various conditions (time, temperature, and atmosphere). The porous Ni xPt1- x alloy as a catalyst for the hydrogenation of propylene has high conversion efficiency (>80%) and low activation energy ( Ea < 20 kJ/mol) at ≥80 °C through the suitable control of the element composition and a pore structure. As a catalyst for the ORR, the catalytic activity of the porous Ni xPt1- x alloy is superior to that of conventional Pt/C (0.115 mA) (0.853 mA/cmPt2 at 0.9 V/cmPt2). This is attributed to the homogeneous alloying of the metal components (Ni and Pt) and the increased accessibility of the reactants to the catalyst, resulting from the unique morphology of the porous Ni xPt1- x alloy, i.e., hierarchical structure with high porosity.