N-doped graphene-supported binary PdBi networks for formic acid oxidation

Highlights: • N-doped graphene supported network-like PdBi catalysts are synthesized. • The PdBi-RGO catalysts are also prepared for comparison. • N-doped graphene is an excellent support to anchor binary PdBi on its surface. • The PdBi-NG catalysts exhibit ultrahigh current density for formic acid oxidation. - Abstract: As advanced electrodes for direct formic acid cells, nitrogen-doped graphene (NG) supported palladium-bismuth nanoparticles have been successfully fabricated through typical wet-chemical method. In studying the effects of NG support on PdBi nanoparticles for the electrooxidation of formic acid, we find that the as-prepared Pd₁Bi₁/NG network-like electrocatalysts exhibit much higher electrocatalytic activities than the Pd₁Bi₁/RGO, Pd₁Bi₁ and commercially available Pd/C catalysts in term of mass activity (1.69, 4.33 and 15.5times higher, respectively). The remarkably enhanced performances are associated with the electron transport between Bi and N, bi-functional effect between Pd, Bi and NG hybrids as well as the well-dispersed network-like structure on the surface of NG. The investigations of PdBi/NG in this work for promoting the electrocatalytic performances and the electron effect between Bi and N will accelerate the development for the field of direct formic acid fuel cells.