Pt₁Bi₁ Intermetallic Structure with Controllable C–H and C–O Bond Activation Ability for Enhanced Diethylene Glycol Oxidation

Abstract

Diethylene glycol serves as a versatile building block for commercial chemicals, and development of its high-value conversion strategies with industrial prospects remains the ultimate goal. Herein, we prepare the bimetallic Pt 2 Bi 1 /TiO 2 catalyst with an intermetallic structure to enable the oxidation of diethylene glycol to high-value-added diglycolic acid. Specifically, the introduction of Bi promotes the formation of hcp-type Pt 1 Bi 1 intermetallic compounds, inducing a transition of Pt from six coordination (Pt−Pt) to three coordination (Pt−Bi). Moreover, the coordinated Bi in the elongated Pt−Bi bond weakens the bridge adsorption of O in the C−O−C bond while the electronenriched Pt modulates the adsorption configuration of diethylene glycol into the η 1 -O-1 type, thereby promoting the activation of the twice C−H bond. Thanks to this synergistic effect, a record-high diglycolic acid selectivity (>75%) is obtained on the Pt 1 Bi 1 intermetallic structure. The catalytic system was further extended to the oxidation of other polyols, including ethylene glycol, 1,3-propanediol, and glycerol, to their diacids with satisfactory catalytic performance.