Tailored Cl<sup>–</sup> Ligation on Supported Pt Catalysts for Selective Primary C–H Bond Oxidation
Chunyan Ma, Chenggong Yang, Hongying Zhuo, Cheng Chen, K. Lu, Fengbang Wang, Zhifu Shi, Hai Xiao, Maoyong Song, Guibin Jiang
Abstract
It is challenging to achieve high selectivity over Pt-metal-oxide catalysts widely used in many selective oxidation reactions because Pt is prone to over-oxidize substrates. Herein, our sound strategy for enhancing the selectivity is to saturate the under-coordinated single Pt atoms with Cl – ligands. In this system, the weak electronic metal–support interactions between Pt atoms and reduced TiO 2 cause electron extraction from Pt to Cl – ligands, resulting in strong Pt–Cl bonds. Therefore, the two-coordinate single Pt atoms adopt a four-coordinate configuration and thus inactivated, thereby inhibiting the over-oxidation of toluene over Pt sites. The selectivity for the primary C–H bond oxidation products of toluene was increased from 50.1 to 100%. Meanwhile, the abundant active Ti 3+ sites were stabilized in reduced TiO 2 by Pt atoms, leading to a rising yield of the primary C–H oxidation products of 249.8 mmol g cat –1 . The reported strategy holds great promise for selective oxidation with enhanced selectivity.