Abstract: 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 WC_1-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/cm² 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.

Key words: Tungsten carbide, Nano-crystalline thin film, Electro-catalytic performance, Nitromethane