Investigation of Hydrogen and Deuterium Spillover on Y Zeolites by FT-IR Microscopy – Rate Determining Steps

Abstract

H-D exchange of zeolitic OH groups due to deuterium spillover was investigated by FT-IR microscopy using two-component Pt/NaY-HNaY zeolite samples. The exchange occurred only, when a platinum-containing sample component was in direct contact with the platinumfree HNaY component. All zeolitic OH groups are involved in the exchange process, whereas their exchange rates differ markedly. The evaluation of the intensities of the OH and OD bands as a function of time after deuterium loading at room temperature led to the conclusion that the diffusion as well as the H-D exchange of the zeolitic hydroxyls are the rate determining steps in the spillover process.