核壳结构碳化钨/碳化钨铁复合材料的制备与电催化活性  

Preparation and Electrocatalytic Activity of Tungsten Carbide and Tungsten-Iron Carbide Composite with Core-Shell Structure

作　　者：陈辉[1] 陈丹[1] 谢伟淼[1] 郑翔[1] 李国华[1,2,3] 

机构地区：[1]浙江工业大学化学工程学院,杭州310032 [2]绿色合成技术国家重点实验室培育基地,杭州310032 [3]浙江工业大学纳米科学与工程技术研究中心,杭州310032

出　　处：《物理化学学报》2014年第5期891-898,共8页Acta Physico-Chimica Sinica

基　　金：国家自然科学基金(21173193; 21301154);浙江省科技厅科技项目(2013C37104;2009R50002-15)资助~~

摘　　要：以铁黄为载体,偏钨酸铵为钨源,将直接包覆与原位还原碳化技术相结合制备了碳化钨/碳化钨铁复合材料.经X射线衍射(XRD)分析和透射电子显微镜(TEM)观察,复合材料的主要物相为碳化钨铁(Fe3W3C)、碳化钨(WC)和碳化二钨(W2C),且构成了以Fe3W3C为核、WC和W2C为壳的核壳结构.采用三电极体系循环伏安法测试了复合材料在酸性、中性和碱性体系中对甲醇的电催化氧化活性.结果表明,与颗粒状碳化钨和介孔空心球状碳化钨相比,复合材料的电催化活性有了明显的提高;进一步研究发现,复合材料的电催化活性不仅受到体系性质的影响,还与其物相组成和微结构相关.上述结果说明,通过控制复合材料的物相组成及微结构,以及反应体系的性质可实现对其电催化活性的调控;同时表明,核壳结构是提高碳化钨催化材料活性的有效途径之一.A tungsten carbide and tungsten-iron carbide composite with a core-shell structure was prepared through a combination of surface coating and in situ reduction-carbonization, using ammonium metatungstate as the tungsten source and iron hydroxide as the iron source. The main crystal phases of the composite were tungsten-iron carbide （Fe3W3C）, monotungsten carbide （WC）, and bitungsten carbide （W2C）. In the core-shell composite, Fe3W3C formed the core, and the shell consisted of WC and W2C. The electrocatalytic activity for methanol oxidation of the composite was measured by cyclic voltammetry with a three-electrode system in acidic, neutral, and alkaline aqueous solutions. The results show that the electrocatalytic activity of the composite is higher than those of tungsten carbide particles and mesoporous hollow microspheres, The activity is affected by the properties of the solution in which the reaction is performed, and is related to the crystal phase and microstructure of the composite. These results indicate that the electrocatalytic activity of tungsten carbide can be adjusted by changing the properties of the reaction solution and controlled by adjusting the crystal phase and microstructure of the composite. Furthermore, the activity can be improved through formation of a core-shell structure; this is an efficient way to improve the electrocatalytic activity of tungsten carbide.

关 键 词：碳化钨 碳化钨铁 核壳结构 电催化活性 调控 

分 类 号：O643.36[理学—物理化学]