Constructing tri-coordinated Al (AlIII) sites to boost complete propane oxidation of the Pt/Al2O3 catalyst

Abstract

Complete oxidation of propane has drawn great attention in the fields of automotive emission control and volatile organic compound elimination. However, it is challenging to achieve high activity of this reaction due to the stability of propane. We here utilize a facile solvothermal method to construct tri-coordinated Al (Al_III) sites on the as-synthesized ST-Al₂O₃ support to alter the properties of supported Pt species. It is demonstrated that Al_III sites facilitate the dispersion and electron enrichment of supported Pt sites. Thus, Pt/ST-Al₂O₃ exhibits a superior activity toward complete propane oxidation, showing a 6.7-fold improvement in the turnover frequency over commercial Pt/Al₂O₃ catalysts. Meanwhile, Pt/ST-Al₂O₃ possesses a distinct reaction route originating from its stronger C–H and C–C cleavage capability, while having excellent activity not only in complete propane oxidation but also in the complete oxidation of other alkanes (CH₄, C₂H₆, and n-C₄H₁₀). In addition, the Al_III construction strategy is successfully extended to more cases, e.g., Pd/ST-Al₂O₃ with higher Pd dispersion and electron density. This work provides a promising strategy for the control of the oxide support for advanced design and synthesis of alkane oxidation catalysts.