Spatial isolation effect improves the acidity and redox capacity of ZSM-5 encapsulating Pt catalyst to achieve efficient toluene oxidation

Abstract

This paper introduces a novel approach of encapsulating Pt nanoparticles within the pores of a molecular sieve. By comparing the dispersion, reducibility and surface acid sites, the effect of the combination of molecular sieves and Pt particles on the catalytic performance of toluene was studied. The findings demonstrate that Pt nanoparticles were encapsulated within the molecular sieve framework of ZSM-5 molecular sieves using an in-situ synthesis method, exhibiting remarkable catalytic activity towards toluene oxidation (T90=172 ℃). Mainly due to the spatial confinement of the ZSM-5 molecular sieve framework reduces the size of Pt nanoparticles, enhances their dispersion of the Pt@ZSM-5 catalysts. In addition, the space separation effect of ZSM-5 on Pt metal enhances their interaction and promotes the valence state conversion of Pt species. It leads to a large number of acid sites and oxygen vacancies in the catalyst, which improves the adsorption and migration of toluene, thereby improving the catalytic activity. This study will provide valuable insights into the preparation of new nanocatalysts and the catalytic treatment of toluene.