Elucidating the promotion mechanism of the ternary cooperative heterostructure toward industrial-level urea oxidation catalysis

Abstract

From the perspective of electronic structure modulation, it is highly desirable to rationally design the active urea oxidation reaction (UOR) catalysts through interface engineering. The binary cooperative heterostructure systems have been shown significant enhancement for catalyzing UOR, but their performance still remains unsatisfactory for industrialization because of the unfavorable intermediate adsorption/desorption and deficient electron transfer channels. In response, taking the ternary cooperative Ni5P4/NiSe2/Ni3Se4 heterostructure as the proof-of-concept paradigm, a catalytic model is rationally put forward to elucidate the UOR promotion mechanism at the molecular level. The rod-like Ni5P4/NiSe2/Ni3Se4 nanoarrays with three-phase heterojunction are experimentally fabricated on Ni foam (named as Ni5P4/NiSe2/Ni3Se4/NF) via simple two-step processes. The density functional theory (DFT) calculations disclose that construction of Ni5P4/NiSe2/Ni3Se4 heterostructure model not only induce charge redistribution at the interfacial region for creating innumerable electron transfer channels, but also endow it with a moderate d-band center that could help to build a balance between adsorption and desorption of diverse UOR intermediates. Benefiting from the unique rod-like nanoarrays with large specific surface area and the optimized electronic structure, the well-designed Ni5P4/NiSe2/Ni3Se4/NF could act as a robust catalyst for driving UOR at industrial-level current densities under tough environments, offering great potential for commercial applications.