文献类型：期刊文献

英文题名：Vicinal hydroxyl group-inspired selective oxidation of glycerol to glyceric acid on hydroxyapatite supported Pd catalyst

作者：Li, Difan[1];Zhao, Xiuge[1];Zhou, Qingqing[1];Ding, Bingjie[1];Zheng, Anna[1];Peng, Qingpo[1];Hou, Zhenshan[1]

机构：[1]East China Univ Sci & Technol, Sch Chem & Mol Engn, Res Inst Ind Catalysis, Key Lab Adv Mat, Shanghai 200237, Peoples R China

年份：2022

卷号：7

期号：4

起止页码：691

外文期刊名：GREEN ENERGY & ENVIRONMENT

收录：;EI(收录号：20212110402207);WOS:【SCI-EXPANDED(收录号:WOS:000803021000001)】；

基金：The authors are grateful for support from the National Natural Science Foundation of China (21773061, 21978095), Innovation Program of Shanghai Municipal Education Commission (15ZZ031), and the Fundamental Research Funds for the Central Universities.

语种：英文

外文关键词：Hydroxyapatite; Palladium; Glycerol oxidation; Glyceric acid; Vicinal hydroxyl group

摘要：Selective oxidation of glycerol provides a feasible route towards the sustainable synthesis of high value-added chemicals. Herein, the hydroxyapatite (HAP) supported palladium (Pd) species were fabricated by impregnation and subsequent calcination. The as-obtained heterogeneous Pd catalyst afforded not only excellent selectivity to glyceric acid (GLA) up to 90% with 59% conversion of glycerol but also good recyclability by using molecular oxygen as an oxidant under mild conditions. The characterization of catalysts indicated that both the surface basicity and Pd sites on the catalyst played a crucial role in promoting glycerol oxidation. Notably, it demonstrated that the presence of the vicinal hydroxyl group of glycerol molecule can assist the oxidation reaction via forming a coordination between the vicinal hydroxyl group and Ca2+ sites on HAP-derived catalysts. In this catalytic process, the secondary hydroxyl of glycerol kept untouched and the primary hydroxyl of glycerol was converted into carboxyl group, while the Pd species acted as active centers for cooperatively promoting the subsequent oxidation to generate GLA. Additionally, this catalytic system can be extended widely for the oxidative conversion of other vicinal diols into the corresponding alpha-hydroxycarboxylic acids selectively. Isotope labeling experiment using (H2O)-O-18 confirmed that H2O not only acted as solvent but also was involved in the catalytic cycles. On the basis of the results, a possible reaction mechanism has been proposed. The HAP-supported Pd catalytic system has been shown to serve as an effective approach for the upgrading of bio-derived vicinal diols to high value-added chemicals. (C) 2020 Institute of Process Engineering, Chinese Academy of Sciences. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co., Ltd.