Electrooxidation of Thymol or Carvacrol to Obtain Thymoquinone on Defective Pt/CeO2 Catalyst

Abstract Thymoquinone (TQ), a compound with diverse pharmacological benefits, faces limited availability from natural sources. In this study, the design of a highly efficient electrocatalyst, Pt clusters loaded on CeO 2 with rich oxygen vacancies (Vo‐Pt/CeO 2 ), for the electrocatalytic oxidation of thymol (TY) or carvacrol to produce TQ is reported. The introduction of oxygen vacancies to the surface of Vo‐Pt/CeO 2 significantly reduces the adsorption energy of TQ, facilitating its desorption and preventing product accumulation and catalyst poisoning. As a result, Vo‐Pt/CeO 2 demonstrates exceptional electrocatalytic performance, achieving ≈100% selectivity and up to 98% yield of TQ under 1.2 V RHE . In situ, Raman spectroscopy indicates that the electrocatalytic oxidation mechanism of TY involves water attacking the TY intermediate to form thymohydroquinone, which is subsequently oxidized to TQ. Overall, this work provides novel insights into the catalyst design and presents a new strategy for sustainable TQ synthesis.