Abundant oxygen vacancies promote bond breaking of hydrogen peroxide on 3D urchin-like Pd/W18O49 surface to achieve high-performance catalysis of hydroquinone oxidation

As a typical carcinogenic phenolic environmental pollutant, hydroquinone (HQ), its effective catalytic conversion is particularly urgent for environmental protection. However, the development of low-cost, high-efficiency catalysts still faces many challenges. Furthermore, the mechanism for efficient catalysis has not been established. In this paper, a trace amount of Pd-supported 3D urchin-like Pd/W18O49 composite in an aqueous solution was reported as a high-quality catalyst for the H2O2 catalytic oxidation of hydroquinone (HQ) to benzoquinone (BQ) with a turnover frequency (TOF) of 1750 h−1, exceeding commercial catalyst. Through experiments combined with density functional theory (DFT) calculations analysis, this excellent catalytic effect is mainly attributed to the existence of an electronic induction effect between W18O49 and Pd nanoparticles (NPs). Meanwhile, the abundant oxygen vacancies on the surface of W18O49 can stabilize the·OH radicals generated from the decomposition of H2O2, thus promoting the breakage of O-O bonds to generate more·OH radicals and achieve an effective oxidation reaction. In addition, the influencing factors such as catalyst and HQ concentration, solution pH, solvent, various inorganic and organic interferences were comprehensively investigated. The 3D urchin-like Pd/W18O49 catalyst also showed an excellent effect on the catalytic oxidation of HQ derivatives with high TOFs.