Gold Decorated Hydroxyapatite–CeO2 Enabled Surface Frustrated Lewis Pairs for CO Oxidation

Abstract

The activation of molecular oxygen (O2) holds the fundamental step for reaction mechanism of carbon monoxide oxidation. Surface frustrated Lewis pairs (SFLPs) with sterically hindered Lewis acid–base pairs are proven to activate small molecules, such as hydrogen. However, the activation of molecular O2 on SFLPs remains unexplored. Herein, the construction of SFLPs in Au decorated hydroxyapatite (HAP)–CeO2 heterojunction is reported. The coordinately unsaturated Lewis acidic Ce3+ and the Lewis basic OH− group in HAP enable the activation of O2 molecules to O2−–Ce3+ species for carbon monoxide (CO) oxidation. The active site is identified based on the comprehensive in situ electron paramagnetic resonance, in situ diffuse reflectance infrared Fourier transform spectroscopy, X‐Ray absorption spectroscopy, and theoretical simulation. The results provide a new strategy to construct SFLPs sites for O2 molecule activation and the subsequent CO oxidation.

Keywords

• heterojunctions
• O2 molecular activations
• supported catalysts
• surface chemistry
• surface frustrated Lewis pairs