Promoting ordering degree of intermetallic fuel cell catalysts by low-melting-point metal doping.

Carbon supported intermetallic compound nanoparticles with high activity and stability are promising cathodic catalysts for oxygen reduction reaction in proton-exchange-membrane fuel cells. However, the synthesis of intermetallic catalysts suffers from large diffusion barrier for atom ordering, resulting in low ordering degree and limited performance. We demonstrate a low-melting-point metal doping strategy for the synthesis of highly ordered L1-type M-doped PtCo (M = Ga, Pb, Sb, Cu) intermetallic catalysts.

Pentacoordinate Al Sites Anchoring Synthesis of Palladium Intermetallic Catalysts on AlO Supports.

Size control of supported Pd-based intermetallic nanoparticles (i-NPs) remains a major challenge because the required high-temperature annealing for atomic diffusion and ordering easily causes metal sintering. Here, we described a pentacoordinate Al site (Al) anchoring approach for the preparation of Pd-based i-NPs with controlled size, which takes advantage of the strong chemical interaction between Al sites and Pd-based i-NPs to realize size control. We synthesized six types of Pd-based i-NPs, and four of them can remain an average particle size of <6 nm.