Nanoporous (Pt_1-xCo_x)₃Al intermetallic compound as a high-performance catalyst for oxygen reduction reaction

Nanocatalysts that boost the sluggish kinetics of oxygen reduction reaction with a long-term durability are crucial for widespread use of low-temperature fuel cells. Here we report a nanoporous intermetallic compound typically composed of platinum–cobalt–aluminum intermetallic core with in-situ grown atomic-layer-thick Pt skin as a novel oxygen-reduction-reaction nanocatalyst with remarkably enhanced performance. Both Pt and Co atoms thermodynamically prefer to locate nearby Al element within face-centered cubic Pt₃Al matrix via the formation of strong Pt–Al and Co–Al bonds, which not only enable synergistic ligand and compressive strain effects to moderately weaken the oxygen adsorption energy of Pt skin, but alleviate the evolution of surface Pt atoms to protect against the further dissolution of less-noble Co and Al. As a result, the nanoporous platinum–cobalt–aluminum nanocatalyst exhibits specific activity of 3.40 mA cm⁻² _Pt and mass activity of 2.2 A mg⁻¹ _Pt for the oxygen reduction reaction at 0.9 V versus reversible hydrogen electrode (∼13- and ∼20-fold enhancement relative to commercially available platinum nanoparticles supported carbon) with an exceptional durability, showing genuine potential as cathode catalyst in next-generation electrochemical energy conversion devices.