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

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 (T 90 =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. Due to the spatial isolation effect, Pt particles dispersed uniformly in the molecular sieve framework of ZSM-5, the interaction between Pt and molecular sieve was enhanced, the content of Pt 0 was increased and oxygen vacancy was generated. The change of valence state also enhances the acidity and redox performance, promotes the adsorption of toluene, and finally realizes the efficient degradation of toluene. • Pt nanoparticles were encapsulated within the molecular sieve framework of ZSM-5. • Space isolation effect improves the interaction between the Pt species and the molecular sieve network. • Good redox activity and abundant acid sites promote the efficient oxidation of toluene.