Pt/Nb‐WO_x for the chemoselective hydrogenolysis of glycerol to 1,3‐propanediol: Nb dopant pacifying the over‐reduction of WO_x supports  

Pt/Nb-WO_x催化甘油选择氢解制1,3-丙二醇:Nb掺杂抑制WO_x的过度还原（英文）

作　　者：Man Yang Xiaochen Zhao Yujing Ren Jia Wang Nian Lei Aiqin Wang Tao Zhang 杨曼;赵晓晨;任煜京;王佳;雷念;王爱琴;张涛(中国科学院大连化学物理研究所催化基础国家重点实验室,辽宁大连116023;中国科学院大学,北京100049;西北农林科技大学林学院,陕西杨凌712100)

机构地区：a State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, Liaoning, China b University of Chinese Academy of Science, Beijing 100049, China c College of Forestry, Northwest A＆F University, Yangling 712100, Shaanxi, China

出　　处：《Chinese Journal of Catalysis》2018年第6期1027-1037,共11页催化学报（英文）

基　　金：supported by the National Natural Science Foundation of China (2169008, 21690084, 21673228, 21303187, 21403218);the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB17020100);DICP ZZBS 201612;Key Projects for Fundamental Research and Development of China (2016YFA0202801)~~

摘　　要：Selective hydrogenolysis of glycerol to 1,3‐propanediol（1,3‐PD） is an important yet challenging method for the transformation of biomass into value‐added chemicals due to steric hindrance and unfavorable thermodynamics. In previous studies, chemoselective performances were found de‐manding and sensitive to H2 pressure. In this regard, we manipulate the chemical/physical charac‐teristics of the catalyst supports via doping Nb into WOx and prepared 1D needle‐, 2D flake‐, and 3D sphere‐stack mesoporous structured Nb‐WOx with increased surface acid sites. Moreover, Nb dop‐ing can successfully inhibit the over‐reduction of active W species during glycerol hydrogenolysis and substantially broaden the optimal H2 pressure from 1 to 5 MPa. When Nb doping is 2%, sup‐ported Pt catalysts showed promising performance for the selective hydrogenolysis of glycerol to 1,3‐PD over an unprecedentedly wide H2 pressure range, which will guarantee better catalyst sta‐bility in the long run, as well as expand their applications to other hydrogen‐related reactions.随着生物柴油产业的快速发展,甘油作为副产物大量过剩,通过甘油氢解制备具有高附加值的丙二醇既符合原子经济的原则,又具有重要的学术研究意义和应用价值.其中选择氢解制备1,3-丙二醇,因其产物在新型聚酯材料合成中的重要应用而备受关注,被认为是最具工业应用潜力的甘油转化工艺之一.但是由于反应空间位阻效应和热力学上的限制,甘油氢解制备1,3-丙二醇仍存在很大的挑战.目前,可高选择性制得1,3-丙二醇的催化剂体系主要是铱–铼催化剂和铂–钨催化剂两类;且反应通常需要较苛刻的压力.在我们的前期工作中,单原子/准单原子Pt催化剂(Pt/WO_x)成功突破了这一压力壁垒,实现了在较低(1 MPa)氢气压力下优异的甘油选择氢解制1,3-丙二醇活性;但是该催化剂的耐压性能较差,是长期反应后失活的一个主要原因,且随着氢气压力的进一步升高,Pt/WO_x催化剂活性大幅下降.研究发现,在高压氢气下,单原子/准单原子催化剂Pt/WO_x中的WO_x易被过度还原,导致催化剂失活,大大限制了该系列单原子催化剂在涉氢催化反应中的应用.因此,通过载体改性设计制备具有良好氢气稳定性的载体,有可能拓宽催化反应的氢压窗口.一般来讲,可以通过掺杂来改变载体的电子结构、表面化学性质等,进而改变催化剂活性、选择性和稳定性.为了提高单原子/准单原子催化剂(Pt/WOx)在高压氢气中的稳定性,本文采用原位掺杂法制备了一系列具有不同掺杂量、结构、及物化性质的Nb-WOx载体,并通过物理吸附,XRD,SEM,HRTEM,Raman,XPS对其进行表征.结果发现Nb掺杂的介孔WO_x仍保持较高的比表面积(~136 m^2/g);且当Nb掺杂量增加至2 wt%时,WO_x由一维针状堆积转变为二维片状堆积;至5 wt%时,变为三维球状堆积.以所得的Nb-WO_x为载体,我们制备了一系列Pt高度分散的Pt/Nb-WO_x催化剂,并考察了其在甘油选择性氢�

关 键 词：Nb‐doped WOx Glycerol 1 3‐propanediol Selective HYDROGENOLYSIS 

分 类 号：TQ223.162[化学工程—有机化工]