Sub‐3 nm Intermetallic Ordered Pt(3)In Clusters for Oxygen Reduction Reaction

Industrial applications of Pt‐based oxygen‐reduction‐reaction (ORR) catalysts are limited by high cost and low stability. Here, facile large‐scale synthesis of sub‐3‐nm ordered Pt(3)In clusters on commercial carbon black as ORR catalyst that alleviates both these shortcomings is reported. As‐prepared Pt(3)In/C exhibits a mass activity of 0.71 mA mg(−1) and a specific area activity of 0.91 mA cm(−2) at 0.9 V vs reversible hydrogen electrode, which are 4.1 and 2.7 times the corresponding values of commercial Pt/C catalysts. The as‐prepared ordered Pt(3)In/C catalyst is also remarkably stable with negligible activity and structural decay after 20 000 accelerated electrochemical durability cycles, due to its ordered structure. Density‐functional‐theory calculations demonstrate that ordered‐Pt(3)In is more energetically favorable for ORR than the commercial Pt/C catalysts because ∆G (O) is closer to the peak of the volcano plot after ordered incorporation of indium atoms.