Design a promising non-precious electro-catalyst for oxygen reduction reaction in fuel cells

摘要

? 2022 Hydrogen Energy Publications LLCWe utilized quantum-chemical computations for computing the thermodynamic variations in the Gibbs free energy of the potential reaction steps in the oxygen reduction reaction (ORR) of the nickel- and nitrogen-doped graphene (NiN3-Gr) catalyst's active center. We observed the consistency of the energies of adsorption for all O-containing intermediates. The great thermodynamic driving forces (or motives) for reducing OOH into 2OH? or O? and the minor motives for generating H2O2 show the advantageousness of following a 4-electron pathway compared to a 2-electron one. This reaction's rate-determining step has 0.94 eV energy barrier that is associated with the first H2O molecule formation. According to the thermodynamics results, at lower than 0.51 V electrode potential by the 4e? pathway, the elementary steps of ORR are downhill. The last step, which is the OH reduction into H2O with the largest value of ΔG, acts as the 4e? pathway's thermodynamic RDS. Experimental scientists can use the theoretical results achieved in the current study in order to synthesize and select appropriate combinations of NiN3-Gr for applications in fuel cells.