PRELIMINARY TREATMENT WITH AMMONIA IN REDUCTION OF CuY ZEOLITE

Abstract
The reduction process of CuY zeolite has been investigated in temperature programmed experiments. The reduction of Cu2+ ions with H2 occurred by a two-step mechanism, via Cu+ ions to Cu metal. In the first step of reduction NH3 was used as the reducing agent instead of H2. Copper particles in the reduced zeolite with the NH3-pretreatment were uniformly dispersed compared to those without the NH3-pretreatment. The average diameters of the particles were estimated to be 8.4 nm for the former and 18.5 nm for the latter.