Pt-WC/Mnt三元纳米复合材料的制备及其电催化性能

以剥离后的蒙脱石(Mnt)片层为载体、六氯化钨(WCl6)为钨源,通过浸渍负载及原位还原碳化获得了碳化钨(WC)与蒙脱石(Mnt)纳米复合材料,然后将氯铂酸(H2PtCl6)通过浸渍负载于复合材料上,并在氢气(H2)中还原得到Pt-WC/Mnt三元纳米复合催化材料。采用X射线粉末衍射和透射电子显微镜对三元纳米复合催化材料的物相、形貌和结构进行表征,采用三电极体系和循环伏安法测试了样品的电催化性能。结果表明:样品物相主要为WO3和WC,蒙脱石片层结构明显,铂(Pt)纳米粒子均匀分布于WC/Mnt复合材料的外表面。Pt-WC/Mnt三元纳米复合材料对甲醇电催化氧化具有较高的催化活性,并且在酸碱体系中均具有良好的稳定性。

Preparation of Pt-WC/Mnt nano-composite and its electrocatalytic activity

A tungsten carbide(WC)montmorillonite(Mnt)nanocomposite(WC/Mnt)was fabricated by combining a chemical immersion approach with a reduction-carbonization method in-situ using tungsten hexachloride as tungsten source and exfoliated Mnt as support.The nanocomposite supported Pt nanoparticles(Pt-WC/Mnt)with uniform size was prepared using H2 as reductant and H2PtCl6 as Pt precursor.The crystal phase,structure and morphology of the ternary nanocomposite catalysts were characterized by X-ray diffractometry and transmission electronic microscopy.The electrocatalytic activity of Pt-WC/Mnt as-prepared was investigated using three-electrode system and cyclic voltammetry.The results show that the crystal phase of the catalyst composed of WC and WO3.After reduced by H2,the layer structure of Mnt in the composite is obvious,Pt particles of about 4 nm in diameter disperse on the outer surface of the WC/Mnt composite uniformly.The Pt-WC/Mnt catalysts exhibit high electrocatalytic activity for methanol electrocatalytic oxidation and good stability in acidic and alkaline electrolyte.These can be attributed to the typical structure of the composite and the synergistic effect among all the components of the ternary nanocomposite,which outlines a foundation for the practical application of Pt-WC/Mnt ternary nanocomposites.