Zr-based Laves phases with nitride/hydride ions for ammonia synthesis

Abstract

Early transition metal-based intermetallic compounds, such as ZrV2, ZrMn2, and ZrCr2, can reversibly absorb large amounts of hydrogen and are of great interest for hydrogen storage. The dissociative hydrogen chemisorption can proceed easily on the surface, allowing the rapid formation of intermetallic hydrides. In this study, we present the results of initial NH3 activity tests conducted on various Zr-based AB2-type intermetallic compounds, free of precious transition metals and rare earth metals. A dissociative hydrogen chemisorption together with nitrogen storage proceeds on AB2-type Laves phase intermetallic compounds accompanied by a lattice expansion. The formed intermetallic nitride hydride ZrCr2N0.4H1.4 exhibits stable catalytic activity as an ammonia synthesis catalyst.