Determination of acid sites in porous aluminosilicate solid catalysts for aqueous phase reactions using potentiometric titration method

Kai Yu, Narendra Kumar, Atte Aho, Jorma Roine, Ivo Heinmaa, Dmitry Murzin, Ari Ivaska

Research output: Contribution to journalArticleScientificpeer-review

18 Citations (Scopus)

Abstract

A potentiometric acid–base titration method was developed to characterize the acid–base properties of H-Beta-25, H-Beta-300, H-Ferrierite-20 and Si-MCM-48 zeolites in aqueous solutions. The method is based on linearization of the titration curve. The zeolite powders were dispersed in a sodium nitrate solution which was then titrated with a standard solution of sodium hydroxide. Various acid sites were found in the studied zeolites, and both the protonation constants and the concentrations of these acid sites were determined. The chemical composition (aluminum and silicon), distribution of the aluminum sites, crystallinity as well as the acidic properties of the titrated zeolites were compared with those of the pristine zeolites by using Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES), X-ray Diffraction (XRD), 27Al NMR spectroscopy and the commonly used gas phase Fourier Transform Infrared spectroscopy (FTIR) of pyridine adsorption method.
Original languageUndefined/Unknown
Pages (from-to)117–124
JournalJournal of Catalysis
Volume335
DOIs
Publication statusPublished - 2016
MoE publication typeA1 Journal article-refereed

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