三元过渡金属氮化物介孔纳米晶体的合成及性能研究

Transition metal nitride is a class of interstitial crystals. Nitrogen atoms occupy the interstitial sites in the lattice, resulting in the shrink of the d band, the enhancement of density of states and the ability of surface d-electron donating. Similar to group VIII noble metals, transition metal nitrides exhibit great potential as efficient catalysts for hydrogen evolution reaction (HER) and oxygen reduction reaction (ORR). By adopting temperature-programmed nitridation method, the development of novel ternary mesoporous transition metal nitride with tunable components, morphologies, size, pore-size ordering will be achieved. Moreover, the huge specific surface area and enough channels for diffusion and mass-transfer will accelerate the kinetics of electrocatalytic process occurring in the interface among gas, electrode and electrolyte. And the reaction speed of rate-limiting step can be further tuned by changing the width and location relative to the Femi level of d-band. These research results together with the further explorations of transition metal nitride in supercapacitor will broaden the understanding on the structure and function of ternary transition metal nitride nanocrystals and further increase the application value of the nitride nanocrystals in science, technology and industry fields.

过渡金属氮化物作为金属间充型晶体材料，氮原子随机分布在过渡金属晶格的间隙位点上，导致过渡金属d带收缩，费米能级附近态密度增大以及表面d电子供给能力，具有类似与VIII族贵金属的催化活性，能满足氢析出及氧还原等电化学反应的催化要求。本项目拟采用程控升温氮化前驱体的方法，开发具有介孔结构的新型三元过渡金属氮化物纳米材料，系统研究组分、形貌、尺寸以及孔结构有序性可调的三元过渡金属氮化物的可控生长工艺，利用介孔结构所具备的超大比表面积以及足够多的扩散与传质通道，提高气体-电极-电解液三相界面内电催化反应的动力学性能,进一步通过改变过渡金属d带的宽度以及相对于费米能级的位置调控速率限制步骤反应速度；同时探索介孔三元过度金属氮化物纳米材料在超级电容器方面的应用，以拓宽人们对三元过渡金属氮化物纳米晶体的结构与功能的认识，提高其在科学技术与工业生产领域中的应用价值。

本项目采用水热合成、溶胶-凝胶结合高温煅烧、固相烧结等方法，开发具有介孔结构的新型三元过渡金属氮化物纳米材料。系统研究了组分、形貌可调的三元过渡金属氮化物介孔纳米晶体材料的可控合成工艺与生长机理。系统研究了该类材料的氢析出和氧还原催化性能，获得了纳米晶的组分、孔径、微观结构特性与其氧电极双效电催化活性之间构-效关系的基本规律，最终提高其在科学技术与工业生产领域中的应用价值。