Electrocatalytic Decomposition of Formic Acid Catalyzed by M-Embedded Graphene (M = Ni and Cu): A DFT Study

In this study, the HCOOH decomposition reaction on nickel (Ni)- and copper (Cu)-embedded graphene surfaces was computationally modeled using density functional theory. The charge density of both graphene surfaces was investigated by bader charge analysis and demonstrated by an electron density difference map. The results proved that HCOOH, HCOO, COOH, HCO, H2O, CO, OH and H structures chemically bonded to both graphene sheets. Moreover, the minimum energy reaction path from HCOOH to CO2 and CO on both graphene surfaces was investigated by breaking the C–O, C–H and O–H bonds. The main intermediate of HCOOH dissociation on Ni and Cu embedded graphene substrates was determined as HCOO. The main product of HCOO decomposition on both graphene surfaces was CO2. In comparison to cis-COOH and trans-COOH, CO2 recovery from HCOO on graphene substrates was less favored.The breakdown of trans-COOH on graphene surfaces was of a more minimal-energy reaction pathway than cis-COOH. In addition, the main product of HCO decomposition on both graphene surfaces was determined to be CO. Finally, it was determined that the minimum energy reaction pathway for HCOOH dissociation on both graphene surfaces was HCOOH → HCOO → CO2.