微反应器中的混合对Cu-ZnO催化剂微结构形成过程的影响  

Influence of mixing inside microreactor on microstructural evolution of Cu-ZnO catalyst

作　　者：凌晨[1] 蒋新[1] 汪志勇 秦湘飞 卢建刚[2] 

机构地区：[1]浙江大学化学工程与生物工程学院浙江省化工高效制造技术重点实验室,浙江杭州310027 [2]浙江大学控制科学与工程学院工业控制技术国家重点实验室,浙江杭州310027

出　　处：《化工学报》2018年第2期718-724,共7页CIESC Journal

基　　金：国家自然科学基金项目(21276223;21676236);国家重点研发计划项目(2017YFC0211802)~~

摘　　要：通过对微反应器中流速的调控,研究了混合过程对Cu-ZnO催化剂微结构形成过程的影响。采用Villermaux-Dushman反应体系测量了不同流速下反应器中的混合状况,采用X射线衍射(XRD)、高倍电镜线扫(EDS)、X射线光电子能谱(XPS)分析了对应流速下制备得到的前体和氧化物的结构。结果显示,混合强度增加,前体中的Cu2+、Zn2+分布更为均匀,绿铜锌矿的比例减小,锌孔雀石中的Zn含量提高;进而导致其热分解形成的氧化物中Cu-Zn分布也更为均匀,Cu O-ZnO界面增加,Cu O晶粒粒径减小。研究表明,沉淀反应时混合条件的改变,导致后续系列中间产物中Cu-Zn分布的差异,通过这一路径,混合对反应的影响最终作用于催化剂结构。The influence of mixing inside the microreactor on the microstructural evolution of Cu-ZnO catalyst was investigated by regulating the flow rate. Mixing efficiency in the microreactor was measured by Villermaux-Dushman reaction system under different flow rates, and the structures of precursor and oxide were characterized by X-ray powder diffraction（XRD）, energy dispersive spectroscopy（EDS） and X-ray photoelectron spectroscopy（XPS）. The results showed that with increase of the mixing intensity, the distribution of Cu^2＋ and Zn^2＋ in precursor becomes more uniform, the fraction of aurichalcite decreases and Zn content in zincian malachite rises. The difference in the precursors acts on the oxides, leading to a more uniform Cu-Zn distribution, a better dispersion between Cu O and ZnO, and the decrease of Cu O size. Above study reveals, it is by the Cu-Zn distribution that the changes of mixing during the precipitation affects the subsequent product and results in the difference in Cu-ZnO catalyst microstructure.

关 键 词：微反应器 混合 纳米结构 共沉淀法 流速 Cu-Zn分布 

分 类 号：TQ426.6[化学工程]