Engineering Pt-Mn2O3 interface to boost selective oxidation of ethylene glycol to glycolic acid

Rational design of desirable active sites is still a grand challenge for the efficient conversion of polyols to value-added products. Herein, we successfully constructed the Pt-Mn2O3 interfacial sites rather than Pt-MnOx solid solution to boost selective oxidation of ethylene glycol to glycolic acid under mild conditions. X-ray absorption spectroscopy and high-resolution transmission electron microscope revealed that the pre-distribution of Mn2O3 inside support unexpectedly induced the formation of Pt-Mn2O3 interfacial active sites with strong electron coupling effect, leading to an unprecedented catalytic activity (turnover frequency: 3196.9 h(-1)) and glycolic acid yield (86.4 %). In addition, quantitative analysis of the intrinsic active sites was performed, and a "volcano-shape" relationship was established between initial reaction rate and Pt/Mn ratio. Moreover, the structure-dependent reaction kinetics and density functional theory calculation revealed that the synergistic effect between the Mn2O3 redox cycle and Pt promotes the adsorption of ethylene glycol and the activation of C-H bond, resulting in the lower activation energy of ethylene glycol oxidation. The outcome of this work offers a promising avenue for the direct construction of efficient Pt-based catalysts with desired active sites.