Phase Engineering of MoO ₃ Catalysts for High‐Yield Pyruvic Acid Production from Lactic Acid Oxidation

Lactic acid, a key platform chemical derived from renewable glycerol (a major byproduct of biodiesel production), holds great potential for the sustainable synthesis of high‐value chemicals such as pyruvic acid. An efficient catalytic process for the oxidative dehydrogenation of glycerol‐derived lactic acid by metal oxides is studied. A series of metal oxides was prepared, and their performance in the aerobic conversion of lactic acid was evaluated. During the performance evaluation, a strong crystal phase effect of MoO ₃ was observed, with α ‐MoO ₃ (orthorhombic phase) and h‐MoO ₃ (hexagonal phase) exhibiting significant differences in catalytic activity and selectivity. Specifically, α ‐MoO ₃ showed a lactic acid conversion rate of only 52.3% and a pyruvic acid selectivity of 41.8%, while h‐MoO ₃ demonstrated superior catalytic performance. The optimal catalyst is h‐MoO ₃ , with a lactic acid conversion rate of 81.6% and a pyruvic acid selectivity of 63.7%. Furthermore, the catalysts were characterized by X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X‐ray photoelectron spectroscopy (XPS), and nitrogen adsorption. XRD and FTIR revealed the transformation from α ‐MoO ₃ to h‐MoO ₃ , while XPS demonstrated the influence of crystal phase on the catalyst's oxidative capability.