TITLE: Correlation of Zeolite ZSM-5 Acid Strength with Catalytic Activity and Selectivity. Final Report.
AUTHOR: D. T. Hayhurst.
INST. AUTHOR: Cleveland State Univ., OH. Dept. of Chemical Engineering.
SPONSOR: Department of Energy, Washington, DC.
PUB. TYPE: Technical Report
PUB. COUNTRY: United States
SOURCE: Department of Energy [DE], Apr 84, 30p.
NTIS ORDER NO.: DE85005415/INW
Isosteric heats of ammonia adsorption were determined for several cobalt and cobalt/thorium impregnated H-ZSM-5. Samples were impregnated to the 3, 6 and 9 wt % levels using an incipient wetness technique and either acetone or water for dissolving the metal nitrate salt. The metal impregnation resulted in a lowering of the maximum heat of ammonia adsorption and in a corresponding lowering of the maximum acid site strength. The ammonia adsorption capacity and adsorption heat was unaltered by a reduction of the metal-impregnated samples in hydrogen, indicating that the incipient wetness method leads to cobalt which was most likely ion-exchanged into the zeolite rather than impregnated into the sieve in a reducable form. In addition, the impregnated cobalt caused a slight steric hinderance to the diffusion of n-butane into the metal-loaded zeolite. The use of either water or acetone for dissolving the metal nitrate salt altered the acid-strength distribution. Water was found to lower the acid-site strength to a greater degree than the acetone. 11 references, 8 figures. (ERA citation 10:018787)
REPORT NUMBER: DOE/PC/51258-T1
CONTRACT NUMBER: AC22-82PC51258