Proton affinities of Brønsted hydroxy groups in H-forms of zeolites and SAPOs are determined by an FTIR study of the low-temperature adsorption of carbon monoxide. This method reveals the range of heterogeneity of Brønsted hydroxy groups associated with unmodified zeolites where only one band interacting with carbon monoxide is evident in the infrared spectrum. Three types of acid hydroxy groups associated with different IR bands are detected in a modified zeolite (US-Y), (i) strongly acidic [3599 cm–1, proton affinity (Epa)= 1112 kJ mol–1], (ii) medium acidic (3627 cm–1, Epa= 1142 kJ mol–1) and (iii) weakly acidic (ca. 3740 and 3675 cm–1, Epa= 1192 ± 29 kJ mol–1).
No takes yet. Share an insight, caveat, or question.
Макарова et al. (1994) studied this question.
Synapse has enriched 5 related papers. Consider them for comparative context: