C2N-supported single metal ion catalysts for HCOOH dehydrogenation

Abstract

High catalytic performance of a single-atom transition metal ion (TM^x+) anchored on the two-dimensional (2D) C₂N lattice is predicted for HCOOH dehydrogenation. Considering the Co²⁺, Cu²⁺ and Ni²⁺ non-noble metal ions supported by C₂N, we use density functional theory to demonstrate dehydrogenation energy barriers as low as those for pure Pt and Pd catalysts. The high catalytic performance is ascribed to the reaction occurring through a dual-active center composed of TM^x+ and a nearby N atom of C₂N. Specifically, C₂N–Co²⁺ in the low spin state (S = 1/2) greatly promotes HCOOH dehydrogenation by decreasing the barrier of the rate-determining step to only 0.30 eV, mainly due to the strong ability of TM^x+ to extract charges from HCOOH and C₂N. The obtained mechanistic insights help the rational design of single-atom based transition metal ion catalysts supported by 2D materials.