The Distribution of the Acid Strength on Zeolite Catalyst — Estimation from the Heats of Adsorption —

Publisher Website
Google Scholar
Abstract
The distribution of the acid strength on two zeolites, 13X and 10X, and on the copper form of X-type zeolite were estimated from the differential heats of n-butylamine adsorption in a benzene solution. The acid sites on these zeolites were revealed to have two kinds of acid strengths, that is, the cation-dependent one and the cation-independent one. The former corresponds to the stronger acid strength, and the latter, to the weaker. The IR spectra of the residual surface OH groups on these catalysts were also investigated. The strongest acid sites on each zeolite were considered to be those of the cation-dependent OH group which has the lowest frequency. The interaction between surface OH groups and immersed benzene was assumed to be a π-type hydrogen bond.