Preparation Of Metal Nitrides And Application For Proton Exchange Membrane Fuel Cells

Proton exchange membrane fuel cells（PEMFCs）not only have very high energy conversion efficiency,but also don’t produce pollutants.The main bottle-neck of PEMFCs is the inhibitory chemical reaction kinetics of oxygen reduction reaction（ORR）.Currently,platinum supported on carbon shows the best reaction activity in ORR.However,platinum is very expensive for its limited natural resources.So much more research work has been developed to explore new non-noble metal catalysts（NNMCs）for ORR instead of the platinum.Transition-metal nitrides are considered as the most promising and appropriate catalysts for ORR,owing to the same features with precious metal.In this dissertation,a new ternary nitride Co₃ ZnN supported on nitrogen-doped carbon black（N-CB）has been successfully synthesized through a direct nitridation of stoichiometric ratio of metal salts and carbon black.The typical Co₃ZnN/N-CB nanoparticles can serve as an efficient non-noble metal electrocatalyst for ORR and demonstrate excellent electrocatalytic performance with high activity and high stability.Ni₃ ZnN microspheres was prepared through nitriding mixture of NiO and ZnO with a certain ratio.Electrochemical test showed that Ni₃ ZnN microspheres displayed favourable performance for ORR.Similarly,Fe₃ ZnN microspheres was synthesized by direct nitriding stoichiometric ratio of metal salts.It was found that Fe₃ ZnN microspheres also presented good electrocatalytic property and outstanding stability for ORR.