Fig. 4: Theoretical analysis of the atomic reaction pathway on the NiFe-Fe3O4 catalyst.
From: Looping metal-support interaction in heterogeneous catalysts during redox reactions
a DFT calculated Gibbs free energy diagram for the hydrogen oxidation reaction on NiFe-Fe3O4 (blue solid), and Fe-Fe3O4 (red dashed). Insets show optimized structures of intermediate states. Cyan, pink, red, and pale turquoise balls display Ni, Fe, O, and H atoms, respectively. b Amount of accumulated oxygen atoms on NiFe and Fe nanoparticles from NN-MD simulations, showing that NiFe facilitates the migration of lattice oxygen from the Fe3O4 to the NiFe nanoparticle. c Side and top view of NiFe-Fe3O4 after 20 ps NN-MD simulation. d Energy profile for activated Fe atom transfer on Fe3O4. e Schematics representation of the mechanisms underlying the LMSI effect in hydrogen oxidation on the NiFe-Fe3O4 catalyst.
