Intermetallic Catalysts Consisting of Early 3d Transition Metals and p-Block Metals for Ammonia Decomposition

Abstract

Intermetallic catalysts were investigated for ammonia decomposition, a key technology to extract hydrogen from an ammonia source as a hydrogen carrier. Since Mn, Cr, and V were active in pure 3d-transition metal catalysts, their IMCs with p-block metals were selected. The pure Mn, Cr, and V were nitrided during the reaction, while their IMCs resisted the nitridation. In the Cr- and V-based IMC catalysts, a larger composition of Cr and V resulted in a larger conversion. The Cr₃X and V₃X catalysts exhibited a high activity with any X elements. These results indicate that in IMC catalysts for ammonia decomposition, the activity is dominated by transition metals, and the resistivity against nitridation is improved by p-block metals.