A dynamic structure evolution and reaction pathway over Ni₂P for enhancement toward furfural oxidation

The electrocatalytic conversion of furfural (FF) holds a great promise for value-added furoic acid (FA) generation. However, the dynamic evolution of the catalyst surface during the reaction has seriously hindered our comprehensive understanding of the catalytic process and mechanism. In this paper, we discovered active phase over Ni2P strongly depends on the applied potential. Specifically, Ni2P serves as active phase at 1.30-1.40 VRHE and FOR occurs in a direct way. While the in-situ formed single oxide layer of Ni2P-Ni(OH)2 heterostructure from surface reconstruction dramatically enhances FOR in an indirect way at 1.40-1.60 VRHE, resulting in 85 % FA selectivity and 87 % faradaic efficiency (FE) after deducting FF Cannizzaro reaction. After exceeding 1.60 VRHE, OER will have strong competition with the Ni(OH)2 formation. The proposed dynamic heterostructure model of Ni2P-Ni(OH)2 derived from Ni2P has been validated for its universality to other X-ides (NiS and NiSe2) for FOR and other nucleophilic reagents.