Smart and responsive zeolite catalysts for toluene “storage-oxidation” cycling removal

"Storage - oxidation" cycling provides a novel and efficient route for VOCs' removal. Herein, Cu and Ag modified β zeolite with different SiO2/Al2O3 ratio were prepared as smart and responsive materials for toluene removal. The storage strength for toluene on the metal sites (ion-exchange sites, metallic clusters and nanoparticles) and zeolite substrate (acid sites and channels) were discriminated, and the corresponding regeneration either by in-situ thermal oxidation or plasma assisted oxidation was coupled to fulfil the "storage-oxidation" cycle. By virtue of the collaboration of identified Cu2+ and Ag+ for toluene storage, a Cu2.0Ag3.0/β-25 catalyst was designed with high storage capacity (0.41 mmol/g) and adequate strength for trapping toluene, being available for in-situ thermal regeneration. In this study, the location of Cu and Ag species in β zeolite has been modulated to enable such smart and responsive materials available for toluene "storage and in-situ oxidation" cycling, which provides a general guidance for BTEX elimination.