PtAg Alloy Nanoparticles Embedded in Polyaniline as Electrocatalysts for Formate Oxidation and Hydrogen Evolution

We successfully synthesized partly crystalline polyaniline (c-PANT) induced by PtAg alloy nanoparticles (c-PANI@PtAg). The liquid phase reduction PtAg nanoparticles were directly embedded in the c-PANI on a Pt sheet (c-PANI@PtAg/Pt) by in situ polymerization. c-PANI@ PtAg/Pt demonstrated excellent electrocatalysis for formate oxidation reaction (FOR) and hydrogen evolution reaction (HER). The ordered structure of c-PANI showed a peak-separation effect and therefore significantly enhanced the catalytic path selectivity of c-PANI@PtAg/Pt for FOR Meanwhile the current holding ratio after 1000 circles of voltamogram scanning reaches 91.4%. Research on the electrocatalysis of cPANI@PtlAg0.5/Pt for HER indicated the overpotentials at 1.0 mA cm(-2) in both acid and alkaline solutions were more positive than that of pure Pt. Moreover, c-PANI@PtAg/Pt exhibits a much lower overpotential of 68 mV than that of 115 mV of Pt and a smaller Tafel slope of 27 mV dec(-1) than that of 46 mV dec(-1) of Pt.