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

We successfully realized the directional construction of Pt-Mn2O3 interfacial sites (by the combination of in-situ doping and impregnation methods) to boost selective oxidation of ethylene glycol under mild conditions. It is found 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 glycolic acid oxidation activity (turnover frequency: 3196.9 h−1) and glycolic acid yield (86.4 %). [Display omitted] •Enhanced catalytic performance of ethylene glycol oxidation was achieved.•Strong electron coupling effect was revealed in the Pt-Mn interface.•Quantitative analysis of the intrinsic active sites was performed.•The promotion role of Pt-Mn interfacial on reaction mechanism was correlated. 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 CH 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.