层状前驱体法制备多级结构高分散合金催化剂的构效关系研究

项目名称： 层状前驱体法制备多级结构高分散合金催化剂的构效关系研究

项目编号： No.21306008

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 化学工业

项目作者： 冯俊婷

作者单位： 北京化工大学

项目金额： 25万元

中文摘要： 针对目前C2加氢Pd基催化剂存在乙烯选择性低、稳定性差等问题，本项目将开展多级结构高分散纳米合金催化剂结构设计、可控合成及构效关系研究。鉴于前期良好的研究基础和LDHs层状材料的组成、结构及形貌的可调控性，拟选择LDHs为活性金属前驱体，采用原位合成和可控组装技术，设计合成系列多级结构LDHs基前驱体材料；利用LDHs微观结构的整体均匀性，多种活性金属组分在LDHs结构中高度、稳定分散，并且在多级结构中可以实现LDHs纳米晶的定向排列，有效抑制LDHs片层的团聚，进一步提高活性金属的分散度，并强化传质性能；在晶格定位和网阱限域作用下，使前驱体在可控还原条件下拓扑转变为多级结构高分散纳米合金催化剂；考察催化剂的化学组成、尺寸、微介观结构和形貌与催化性能之间的关系，揭示双金属组分的结构效应和电子效应以及催化剂多级结构的协同作用，阐述催化机理，为高性能C2加氢催化剂设计、合成提供一种新的思路。

中文关键词： 纳米合金；高分散；LDHs；多级结构；选择性加氢

英文摘要： Supported Pd catalyst as a traditional catalyst for selective hydrogenation of acetylene suffers from a low selectivity towards ethylene and poor stability.In this project, we intend to design and prepare highly and stably dispersed nano alloy catalysts with hierarchical structures from a novel layered double hydroxides (LDHs) precursor route. By utilizing in-situ synthesis and controllable assembly technology, a series of hierarchical LDHs based precursors containing different kinds of active components will be prepared. Due to the special features of structure, active metal components will highly dispersed in LDHs nano plates. Moreover, the construction of hierarchical structure will effectively prevent the aggregation of LDHs nano plates and therefore further enhance metal dispersion and mass transfer performance. Due to the lattice orientation and net trap effect, the hierarchical LDHs based precursors will structurally transform into hierarchical nano alloy catalysts with high metal dispersion and alloying degree after controllable reduction. A great amount of foundational research of structure design and synthesis of both catalyst precursors and the resulting catalysts will be systematically carried out. The relationship between the structure and catalytic performance together with the catalytic mechanism

英文关键词： nanoalloy；high dispersion；LDHs；hierarchial structure；selective hydrogenation