Glycerol Electrooxidation on Phosphorus-Doped Pt-αNi(OH)2/C Catalysts

摘要

This work investigates the electrooxidation of glycerol in an alkaline environment at non-doped and P-doped Pt-αNi(OH)2 nanoparticles supported on oxidized Vulcan XC-72R carbon.Pt-αNi(OH)2 and PtP-αNi(OH)2 particles with sizes in the range of 3-5 nm were obtained via a one-step chemical reduction approach.The physicochemical characteristics of the asprepared catalysts were studied by inductively coupled plasmaoptical emission spectrometry(ICP-OES),energy dispersive Xray(EDX),X-ray photoelectron spectroscopy(XPS),transmission electron microscopy(TEM),and x-ray diffraction(XRD)techniques.It was determined that the incorporation of phosphorus lead to the formation of amorphous PtP-αNi(OH)2 deposits.TEM analysis showed that the incorporation of phosphorus into the bimetallic Pt-αNi(OH)2 catalyst origins a remarkable reduction in the average size of the nanoparticles with a narrow size distribution.A substantial improvement in the electrocatalytic properties of the Pt-αNi(OH)2 system toward the oxidation of glycerol was observed through P doping.The P-doped electrocatalysts developed a mass current density of 60.3 mAmg_(Pt)~(-1)at 765 mV vs.RHE,which is about 5 and 45 times higher than those of commercial PtRu/C(12.3 mAmg_(Pt)~(-1))and as-synthesized Pt-αNi(OH)2/C(1.5 mAmg_(Pt)~(-1)),respectively.The temperature-dependent experiments displayed that the apparent activation energy for the reaction is halved upon the addition of phosphorus.