Electronic promoter or reacting species? The role of LiNH2 on Ru in catalyzing NH3 decomposition

Abstract

LiNH₂ decomposes to NH₃ rather than N₂ and H₂ because of a severe kinetic barrier in NH_x (x = 1, 2) coupling. In the presence of Ru, however, a drastic enhancement in N₂ and H₂ formation is obtained, which enables the LiNH₂–Ru composite to act as a highly active catalyst for NH₃ decomposition. Experimental and theoretical investigations indicate that Li creates a NH_x-rich environment and Ru mediates the electron transfer facilitating NH_x coupling. A strategy in catalytic material design is thus proposed.