中文摘要：

采用磁控溅射物理气相沉积技术在金属镍基体上制备碳化钨纳米晶薄膜．薄膜具有纳米晶结构，由粒径为20—35nm的晶粒构成，晶粒分布均匀，晶相结构为非化学计量比的碳化钨（WC1-x）．采用电化学方法研究硝基甲烷在纳米晶碳化钨薄膜电极上的电化学还原性能和反应机理．实验结果表明，碳化钨薄膜电极对硝基甲烷电化学还原反应具有较好的催化性能，当电极电位为-0．89V（vs.SCE）时，硝基甲烷还原为甲基羟胺的电流达14．9mA／cm^2，其反应表观活化能为12．3kJ／mol．硝基甲烷在碳化钨薄膜电极上经过一步不可逆的电化学反应还原成甲基羟胺，其控制步骤是电极反应的电荷传递过程．

英文摘要：

The nano-crystalline tungsten carbide thin film was deposited on Ni substrate by magnetron sputtering physical vapor deposition. The morphology and crystal structure of the thin films were characterized by SEM and XRD. The results show that these thin films have nano-crystalline structure, the size of the uniformly grains ranges between 20-35 nm. The main components of the thin film were WC1-x. Electrocatalytic properties and reaction mechanism of nitromethane electroreduction on nano-crystalline tungsten carbide thin film electrode were investigated by electrochemical methods. The experiment result indicates that these electrodes showed a good electro-catalytic activity. Current peak of 14.9 mA/cm^2 of nitromethane electroreduction appeared at -0.89 V（vs. SCE） and the reaction activation energy was 12.3 kJ/mol. The electrocatalytic reduction of nitromethane on these electrodes was a one-step reaction, and the reactions was irreversible. The control step of nitromethane eleroreduction on WC thin film electrode was electron exchange process.