Ammonium functionalization of porous supports for high loading metal catalysts

Abstract

High loading of a metal catalyst on a porous support is desirable to achieve high catalytic performance in many industrial processes involved in heterogeneous metal catalysts. However, at such a high level of loading, metal dispersion becomes very low due to agglomeration of metal particles on the support material. Consequentially, it is difficult to obtain a large metal surface area, which participates in catalytic reaction and eventually removes the chance to increase catalytic activity beyond a certain point. To overcome this problem, the work presented in this thesis addresses an effective method for supporting metal catalysts on porous materials and their catalytic activity in various catalytic reactions. More specifically, ammonium groups are introduced into the porous support to increase the internal basicity of the porous environment. The basic functional groups caused local precipitation of the metal precursors as hydroxide forms preferentially inside the pores, which allowed to design a highly dispersed supported metal catalyst with high loading amount up to 25 wt%. As a result, the supported metal catalysts obtained here exhibited high catalytic performance toward to industrially relevant catalytic reactions.