Electrocatalytic performances of phosphorus doped carbon supported Pd towards formic acid oxidation

A new kind of phosphorus contained carbon support (PC) was fabricated by calcining the mixture of the carbon and triphenylphosphine under nitrogen. The Pd/P-C and Pd/C catalysts were synthesized by liquid reduction method. The catalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). Well-dispersed Pd nanoparticles were obtained and their particle sizes are in the range of 3.5-4.5 nm. Electrochemical measurements demonstrated that when the mixture of carbon and triphenylphosphine were annealed at 800 °C, the activity of the corresponding catalyst (Pd/P-C-800) was enhanced as a factor of 3.14 than the Pd/C catalyst. A negative shift (76 mV than Pd/C) of CO stripping peak and improved stability were observed for the Pd/P-C-800 catalyst. Moreover, faster charge-transfer kinetics of the formic acid oxidation for the Pd/P-C-800 catalyst was determined through electrochemical impedance spectroscopy (EIS) measurements. The better catalytic activity and stability of the Pd/P-C catalyst are ascribed to the doping of phosphorus in the carbon support.