Adsorption and decomposition of Mo(CO)6 in zeolite NaY

Abstract

The adsorption and decomposition of Mo(CO)₆ in zeolite NaY has been examined gravimetrically and spectroscopically. Saturation adsorption at room temperature is 2.1 Mo(CO)₆ per zeolite supercage. Subsequent heating in vacuo at 373 K causes loss of two carbonyl ligands per molybdenum which can be reversed by addition of CO. Heating at or above 473 K causes complete and irreversible decarbonylation, producing zero-valent molybdenum within the zeolite structure. Further uptake of Mo(CO)₆ occurs on subsequent exposure to the vapour at room temperature; zeolites containing up to 157 Mo per unit cell have been prepared by repeated adsorption and decomposition cycles.