Small molecule-assisted synthesis of carbon supported platinum intermetallic fuel cell catalysts

Supported ordered intermetallic compounds exhibit superior catalytic performance over their disordered alloy counterparts in diverse reactions. But the synthesis of intermetallic compounds catalysts often requires high-temperature annealing that leads to the sintering of metals into larger crystallites. Herein, we report a small molecule-assisted impregnation approach to realize the general synthesis of a family of intermetallic catalysts, consisting of 18 binary platinum intermetallic compounds supported on carbon blacks. The molecular additives containing heteroatoms (that is, O, N, or S) can be coordinated with platinum in impregnation and thermally converted into heteroatom-doped graphene layers in high-temperature annealing, which significantly suppress alloy sintering and insure the formation of small-sized intermetallic catalysts. The prepared optimal PtCo intermetallics as cathodic oxygen-reduction catalysts exhibit a high mass activity of 1.08 A mg(Pt)(-1) at 0.9 V in H-2-O-2 fuel cells and a rated power density of 1.17 W cm(-2) in H-2-air fuel cells. Synthesis of small sized Pt intermetallic catalysts remains challenging. Herewith authors prepared 18 binary Pt intermetallic compounds with small particle size by molecule-assisted synthesis strategy to in-situ form the heteroatom-doped carbon shell.

Automated summary

This study reports a small molecule-assisted impregnation approach for the general synthesis of intermetallic catalysts. The molecular additives containing heteroatoms can be converted into heteroatom-doped graphene layers during high-temperature annealing, effectively preventing alloy sintering and ensuring the formation of small-sized intermetallic catalysts.