Abstract:

Supported catalysts are widely used in heterogeneous catalysis processes, in which the interfacial interaction between the active phase and the support and the influence of the interfacial density on the catalytic reaction mechanism and performance have always attracted attention. The main preparation method for traditional supported catalysts is impregnation method, in which a metal precursor is deposited onto the outer surface of support, normally rendering limited contact area and relatively weak interface interaction between the active species and the support. We use the reverse design idea to construct the surrounding catalyst, and develop a simple and universal preparation method, namely the ion exchange reverse loading method, so that the metal ions of the carrier precursor can replace the metal ions of the active metal hydroxide precursor through the ion exchange reaction. After calcination and reduction, a catalyst with an active core surrounded by a carrier is formed. The unique surrounded structure presents not only high interface density and mutually changed interface, but also high stability due to the physical isolation of active phase, revealing superior catalytic performance to the traditional supported catalyst, suggesting the great potential of this new surrounded catalyst as the upgrade of supported catalyst.

Key words: catalyst, surrounded structure, ion-exchange inverse loading, interface, stability

摘要：

负载型催化剂广泛应用于多相催化过程，其中活性相和载体之间的界面相互作用及界面密度对催化反应机制及性能的影响一直以来备受关注。利用反向设计思路构造包围型催化剂，并开发一种简易普适的制备方法，即离子交换逆负载法，使载体前体的金属离子通过离子交换反应取代活性金属氢氧化物前体的金属离子，经焙烧、还原形成活性核被载体包围的催化剂。调控离子交换程度及金属、载体前体种类，得到不同结构及种类丰富的包围型催化剂。相比传统负载型催化剂，包围型结构具有更高的界面密度和相互改变的界面性质，且因活性相被载体物理隔离具有高稳定性，在催化反应中表现出更优越的催化性能，有望成为负载型催化剂的升级版进而推动工业催化技术进步。

关键词: 催化剂, 包围型结构, 离子交换逆负载法, 界面, 稳定性