Synthesis And Performance Of Supported PtTe Intermetalic Electrocatalyst

Proton-exchange membrane (PEM) fuel cells are drawing much attention as theirease of handling, low operation temperatures and high-efficiency energy conversiondevices for transportation and mobile applications. However, common Pt catalystsusually suffer from several disadvantages, such as high costs, easily being poisoned byCO-like intermediate species and the kinetic limitation of the oxygen reduction,blocking the commercialization of PEMFCs. In recent years, Pt-based catalysts are themost popular and effective electrocatalysts for both the anode and the cathode of PEMfuel cells due to the intermetallics are compounds of metals that display crystalstructures different from the constituent metals. Recent efforts to improve theperformance of Pt-based catalysts have focused on controlling the composition, sizeand shape of the materials. The preparation of PtTe/XC-72/rGO ordered intermetalliccompounds is studied in this paper, and the electrochemical performance of thecompounds is researched in the solutions of acid and small organic molecules such asmethanol and formic acid.Ordered intermetallic phase PtTe nanoparticles with an average particle size of4.5nm were first synthesized in a mixed solution of ethylene glycol (EG)/H2O byco-reducing of H2PtCl6and Na2TeO3with subsequent annealing under a reducingatmosphere. The methods, such as powder X-ray diffraction (XRD), transmissionelectron micrograph (TEM), selected area electron diffraction (SAED),energy-dispersed X-ray spectroscopy (EDS) and cyclic voltammetry were employedfor catalyst’s structure and activity characterization. The results show the producedPtTe nanoparticle can be identified as intermetallic phase PtTe and display a strongelectrocatalytic activity toward methanol and formic acid oxidation. This is relatedwith geometric and electronic structure changes of PtTe.The durability for H2SO4and the methanol electro-oxidation reaction (MOR) havebeen evaluated by accelerated durability test (ADT) carried out by scanning theelectrode potential for extended number of cycles in the potential ranges of0.05–0.8Vand0.02–0.8V vs. NHE, respectively. Based on ADT, XRD, XPS and TEM, theelectrochemical stability of PtTe/XC-72was remarkably enhanced compared with thePt/C catalysts, which also could be attributed to the geometric and electronic structurechanges of PtTe. Thus, a new method to improve the stability of intermetallic compounds is raised.