过渡金属改性氮掺杂多孔碳负载Pt催化甘油氧化制备甘油酸  

Catalytic Oxidation of Glycerol to Glyceric Acid over Transition MetalModified Nitrogened-doped Porous Carbon Supported Pt Catalyst

作　　者：柯义虎 朱春梅 李景云 刘海[1,2] 袁红[1,2] KE Yihu;ZHU Chunmei;LI Jingyun;LIU Hai;YUAN Hong(Key Laboratory of Chemical Engineering and Technology,State Ethnic Affairs Commission,Chemical Science and Engineering College,North Minzu University,Yinchuan 750021,China;Ningxia Key Laboratory of Solar Chemical Conversion Technology,North Minzu University,Yinchuan 750021,China)

机构地区：[1]北方民族大学化学与化学工程学院,化工技术基础国家民委重点实验室,宁夏银川750021 [2]北方民族大学宁夏太阳能化学转化技术重点实验室,宁夏银川750021

出　　处：《生物质化学工程》2023年第2期29-40,共12页Biomass Chemical Engineering

基　　金：国家自然科学基金资助项目(21862001);北方民族大学高层次人才项目(2019BGGZ12);北方民族大学研究生创新项目(YCX21143)。

摘　　要：将不同过渡金属掺杂到金属有机骨架化合物中后,通过高温煅烧得到过渡金属改性氮掺杂多孔碳材料(M@NHC),然后通过胶体沉积法生成Pt/M@NHC催化剂,在碱性条件下用作催化剂将甘油氧化成甘油酸。研究表明:过渡金属的种类对甘油的转化率和甘油酸的选择性有较大影响,其中Ni掺杂的Pt/Ni@NHC催化剂的催化活性最佳。结合N_(2)物理吸附、X射线衍射、X射线光电子能谱、CO_(2)程序升温脱附等表征发现:Ni的加入既影响Pt表面电子结构,还能凭借Ni-Pt金属之间的协同作用增强Pt的抗氧化能力;表面N原子的掺杂会增加Pt和吸附氧表面的电子使分子氧快速活化并且产生更多的活性位点。此外,Pt/Ni@NHC催化剂中Pt纳米颗粒在所有催化剂中颗粒最小,有利于催化性能的提高。对Pt/Ni@NHC在不同制备条件下所得催化剂的催化性能进行考察发现:当Ni负载量为3%,在载体煅烧温度800℃,反应压力1 MPa,反应时间6 h的条件下制备的Pt/Ni@NHC具有最佳的催化活性,此时甘油的转化率为63%,甘油酸选择性为75%。After doping different transition metals into metal-organic framework compounds,transition metal modified nitrogen-doped porous carbon material(M@NHC)was obtained by high temperature calcination.Then,Pt/M@NHC catalyst was prepared by colloidal deposition method and evaluated for catalytic oxidation of glycerol to glyceric acid under alkaline conditions.The result showed that the types of transition metals had a great influence on the conversion of glycerol and the glyceric acid selectivity,and the Ni-doped Pt/Ni@NHC catalyst exhibited the best catalytic activity.Combined with the characterization results of N_(2) physical adsorption,X-ray diffraction,X-ray photoelectron spectroscopy,and CO_(2) temperature programmed desorption,it was found that the introduction of Ni not only changed the surface electronic structure of Pt,but also increased the antioxidant capacity of Pt nanoparticles via Ni-Pt synergies between metals.At the same time,the doping of surface nitrogen atoms increased the electrons on the Pt and adsorption oxygen surfaces,which would rapidly activate molecular oxygen and produce more active sites.In addition,Pt nanoparticles of Pt/Ni@NHC had the smallest particle size in all catalysts,which was conducive to the improvement of catalytic performance.The catalytic performance of Pt/Ni@NHC catalysts under different preparation conditions was investigated.The catalyst of Pt/Ni@NHC prepared under the conditions of 3%Ni content,calcination temperature of 800℃,the reaction pressure of 1 MPa and the reaction time of 6 h had the best catalytic performance.At this time,the conversion rate of glycerol was 63%and the selectivity of glyceric acid was 77.4%.

关 键 词：甘油 甘油酸 催化 氧化 负载PT催化剂 

分 类 号：TQ35[化学工程] O643[理学—物理化学]