Valorization of Different Wastes and Their Use for the Design of Multifunctional Eco-catalysts

Abstract

The desire to protect the environment for futuregenerations has led to the reutilization of all recoverableand recyclable wastes. Consequently, different residuesfrom various sources were collected to make mixed compoundsto be used as catalyst supports. Such wastesincluded sand and cement from the building industry,nonreturnable glass bottles, and used tires. The synthesizedsupports were impregnated with molybdophosphoric acid,a heteropolyacid with Keggin structure, and characterizedby potentiometric titration, optical microscopy, SEM?EDS,and textural property analyses. The bifunctional propertiesof the new catalysts were evaluated in two relevant transformationsin green conditions: (i) the selective oxidationof sulfides to sulfoxides using a green oxidant such as tertbutylhydroperoxide, and (ii) the multicomponent synthesisof 3,4-dihydropyrimidinones (Biginelli reaction, catalyzedin acid media).