Preparation of Transition Metal Nitrides via Reduction-Nitridation with Ammonia

High-quality transition metal nitrides have been prepared by direct reduction and nitridation of transitionmetal oxides with ammonia as reductant and nitrogen source. The thermodynamics of reduction and nitridation process was initially analyzed. Then, two kinds of nitrides prepared by the specified process were compared. The effects of reaction temperature and reaction time on the product quality were investigated. It was found that the reaction temperature and time had a significant effect on the reduction and nitridation process. With the increase of reaction temperature and time, the oxygen content was decreased in the product. This method avoids the introduction of other impurity elements except the negligible trace elements accompanied with the raw materials. In the meantime, the final product contains relatively high-nitrogen content and low residual oxygen content. The quality of the products has been greatly improved and fully meets the standards of industrial products.