Hydrides mediate nitrogen fixation

Abstract

Summary: The fixation of atmospheric dinitrogen to ammonia is crucial for the sustainable growth of human society. The reduction of N2 to NH3 needs the inputs of electrons and hydrogens, which could be supplied by hydridic hydrogens. Hydrides are thus at the forefront of research on homogeneous, biological, and heterogeneous nitrogen fixation. In the present report, we discuss representative progress on the exploration of molecular and bulk-phase hydrides for dinitrogen activation and reduction with a focus on the active involvement and function mechanism of reactive hydride compounds in facilitating ammonia production under mild conditions. We conclude that, with the versatile and important roles discovered, hydrides have the power to mediate electron and/or hydrogen transfers for N2 fixation via energetically more accessible pathways, which in turn would stimulate new ideas for the design and development of more efficient catalysts or processes for green ammonia production.