Nickel oxide nanoparticles with oxygen vacancies for boosting biomass-upgrading

The catalytic activity may be improved by introducing oxygen vacancies (Vo) into oxides, but the exact role of oxygen vacancy in 5-hydroxymethylfurfural oxidation reaction (HMFOR) is not clear. It is very important to study the reaction mechanism of oxygen enriched vacancy electrocatalyst and the dynamic behavior of oxygen vacancy. Here, a facile laser ablation strategy is used to fabricate nickel oxide (Vo-NiO) with different oxygen vacancy content for HMFOR. Series characterization show that abundant Vo, low coordination numbers and electron rich structures of Ni sites in Vo-NiO electrode. In-situ Raman electrochemical spectra show that Vo can promote low valent Ni preoxidation at low oxidation potential, which is conducive to the catalyst surface reconstruction and synergistic promote HMF oxidation. Theory calculation confirm the adsorption energy of 5-hydroxymethylfurfural (HMF) on Vo-NiO surface and the density of states increases, which increases the electron conduction rate in Vo-NiO, and promotes HMFOR.