RHODIUM CARBONYL CLUSTERS IN NAY ZEOLITE MADE BASIC BY TREATMENT WITH SODIUM-AZIDE - CHARACTERIZATION BY INFRARED-SPECTROSCOPY

A supported rhodium carbonyl catalyst for CO hydrogenation was prepared by adsorption of [Rh(CO)2(acac)] on NaY zeolite made basic by treatment with NaN3 in methanol. The catalyst was characterized by Diffuse Reflectance Infrared Fourier Transform (DRIFT) infrared spectroscopy in a flow cell in the presence of He, N2, CO, H-2 and CO + H-2. The results provide a partial understanding of the chemistry of the basic zeolite, indicating, for example that it reacts with N2. It also reacts with [Rh(CO)2(acac)], and the resulting species in the presence of CO and CO + H-2 (even during the catalytic reaction of CO + H-2) are characterized by carbonyl clusters. The clusters in the zeolite are stable in the presence of CO + H-2 at 300-degrees-C; this result is consistent with a report of the stability of the catalyst for CO hydrogenation under similar conditions.