碳化钼的结构、制备及应用研究进展

Research Progress on Structure,Preparation and Application of Molybdenum Carbide

将碳原子引入钼的晶格中形成碳化钼时,形成的间充结构具有独特的物理和化学性质,在加氢反应和制氢反应等领域具有优异的催化性能,可与贵金属铂、钯相媲美。碳化钼化学性质活泼,合成方法和实验条件都密切影响着最终产品的物化性质,任何一种反应原料和实验条件发生微小变化,都可能造成碳化钼的晶相结构、晶粒大小、比表面积等产生较大变化,从而改变材料的催化性质。本文对几种典型碳化钼的晶相类型及空间结构分别进行了介绍,分析了影响碳化钼结构的电子性质和几何因素,系统总结了碳化钼的合成策略并指出了不同制备方法的优劣势。以程序升温还原法为例,分析了碳化钼的生长机理,并从碳化终温、升温速率、碳源浓度三方面着重讨论了制备条件对材料的影响。然后总结了碳化钼在加氢反应、制氢反应、传感器及生物医学材料等领域的应用,详细阐述了碳化钼在电催化析氢和CO_(2)加氢转化反应中的催化机理及改进策略,最后基于目前存在的挑战进一步提出碳化钼材料未来的发展方向。

Molybdenum carbide is formed when carbon atoms are introduced into the crystal lattice of molybdenum.This kind of mesenchymal structure has unique physical and chemical properties.This material has excellent catalytic activity in hydrogenation reaction and hydrogen production reaction,and its catalytic performance can be compared with platinum and palladium.Molybdenum carbide has active chemical properties,so the synthesis method and experimental conditions closely affect the physical and chemical properties of the final product.Small changes in the reaction materials and experimental conditions may result in changes in the crystal phase structure,grain size,and specific surface area of molybdenum carbide,thus changing the catalytic performance of the material.This paper reviews the research progress of molybdenum carbide.The crystalline phase types and spatial structure of several typical molybdenum carbides are introduced,the electronic properties affecting the structure of molybdenum carbide are analyzed,the synthetic strategies of molybdenum carbide are summarized systematically,and the advantages and disadvantages of different preparation methods are pointed out.Ta-king programmed temperature carbonization as an example,the growth mechanism is emphatically analyzed,and the influence and importance of preparation conditions on the final synthetic material are discussed from three aspects:final temperature of carbonization,heating rate,and carbon source concentration.The applications of molybdenum carbide in hydrogenation reaction,hydrogen production reaction,sensor,and biomedical materials are reviewed.The catalytic mechanism and improvement strategy of molybdenum carbide in electrocatalytic hydrogen evolution and CO_(2) hydroconversion are introduced in detail.Finally,based on the existing challenges,the future development direction of molybdenum carbide material is further proposed.