Pt<sub>1</sub>Bi<sub>1</sub> Intermetallic Structure with Controllable C–H and C–O Bond Activation Ability for Enhanced Diethylene Glycol Oxidation
Yue Pan, Jie Li, Yinghao Sun, Yu Su, Yu Gu, Xinyu Kuang, Yibin Liu, Xiang Feng, Hui Zhao, Hao Yan, Xiaobo Chen, Xingong Zhang, Chaohe Yang
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 electron-enriched 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.