SOLID ACID CATALYSTS BASED ON SUPPORTED TUNGSTEN-OXIDES

Supported WOx clusters are active and stable catalysts for isomerizati on, dehydration, and cracking reactions. Bronsted acid sites form on W Ox clusters when a lower valent element replaces W6+ or when W6+ cente rs reduce slightly during catalytic reactions. WOx clusters of interme diate size provide the balance between reducibility and accessibility required to maximize the number of surface H+ species in WOx-ZrO2, zir conium tungstate, and oxygen-modified WC catalysts. H-2 is involved in the generation and maintenance of Bronsted acid sites during catalyti c reactions on WOx clusters.