Tailored Cl - Ligation on Supported Pt Catalysts for Selective Primary C-H Bond Oxidation.

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.