| 微反应器中水层对Cu-Zn共沉淀过程的影响 |
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| 引用本文： | 陈鑫超,凌晨,蒋新,陈帅帅,卢建刚. 微反应器中水层对Cu-Zn共沉淀过程的影响[J]. 化工学报, 2018, 69(10): 4261-4268. DOI: 10.11949/j.issn.0438-1157.20180660 |
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| 作者姓名： | 陈鑫超 凌晨 蒋新 陈帅帅 卢建刚 |
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| 作者单位： | 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 |
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| 基金项目： | 国家重点研发计划项目（2017YFC0211802）；国家自然科学基金项目（21276223，21676236）。 |
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| 摘 要： | 探索了利用扩散反应的耦合制备更均匀的铜锌共沉淀物的方法。通过在微反应器中引入水层并调节水层占总流量的比例，制得了高催化活性的Cu/ZnO共沉淀催化剂。采用高倍电镜线扫（HRTEM/EDS）、X射线衍射（XRD）、热重分析（TG）、氢气程序升温还原（H2-TPR）、N2O化学反应法分析催化剂微结构的差异以及演变关系。结果显示，水层占比增加，初始沉淀物Cu-Zn分布更加均匀，陈化得到的前体中锌含量增大，焙烧得到的氧化物CuO和ZnO接触面积增加，相互作用力不断增强，最终提升了催化剂催化活性。通过模型数值分析发现，Zn2+较快的扩散速率部分抵消了其反应速率慢导致的不均匀性；随着水层占比增加，形成均匀沉淀的扩散-反应动态平衡区域增加，产物中均匀沉淀物的比例得以提高。
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| 关 键 词： | 微反应器 共沉淀法 显微结构 模型 数值模拟 Cu-Zn分布 扩散-反应平衡 |
| 收稿时间： | 2018-06-15 |
| 修稿时间： | 2018-07-31 |
Effect of water layer on Cu-Zn co-precipitation in microreactor |
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| CHEN Xinchao,LING Chen,JIANG Xin,CHEN Shuaishuai,LU Jiangang. Effect of water layer on Cu-Zn co-precipitation in microreactor[J]. Journal of Chemical Industry and Engineering(China), 2018, 69(10): 4261-4268. DOI: 10.11949/j.issn.0438-1157.20180660 |
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| Authors: | CHEN Xinchao LING Chen JIANG Xin CHEN Shuaishuai LU Jiangang |
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| Affiliation: | 1. Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture Technology, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, Zhejiang, China;2. State Key Laboratory of Industrial Control Technology, Department of Control Science and Engineering, Zhejiang University, Hangzhou 310027, Zhejiang, China |
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| Abstract: | A method aiming to prepare more uniform Cu-Zn co-precipitate by coupling of diffusion and reaction process was probed in this article and Cu/ZnO co-precipitated catalysts with high catalytic activity were prepared by introducing water layer into the microreactor and adjusting the ratio of water layer to the total flow. The microstructures and evolution process of the catalysts were analyzed by HRTEM/EDS, X-ray diffraction (XRD), thermogravimetric analysis (TG), hydrogen temperature-programmed reduction (H2-TPR), and N2O chemical reaction methods. The results show that the proportion of water layer increases, the Cu-Zn distribution of the initial precipitate is more uniform, and zinc content in the precursor obtained by the aging is increased, the contact area of the oxide CuO and ZnO is increased, and the interaction force is continuously enhanced. Therefore, larger contact area between calcined oxides CuO and ZnO was achieved leading to better dispersibility and stronger interaction with the final catalytic activity of the catalyst significantly enhanced. Numerical analysis based on the model established by MATLAB revealed that the uniformity caused by slower reaction rate of Zn2+ can be inhabited by faster diffusion rate of its own. The diffusion-reaction equilibrium region, defined as capable to obtain uniform precipitate, was enlarged with the increasing ratio of water layer and larger proportion of uniform precipitate was achieved simultaneously. |
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| Keywords: | microreactor co-precipitation microstructure model numerical simulation Cu-Zn distribution diffusion-reaction equilibrium |
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