Acid-modified clinoptilolite as a support for palladium-copper complexes catalyzing carbon monoxide oxidation with air oxygen

Tatyana L Rakitskaya; Tatyana A Kiose; Kristina O Golubchik; Alim A Ennan; Vitalia Y Volkova

doi:10.1186/s13065-017-0256-6

Acid-modified clinoptilolite as a support for palladium-copper complexes catalyzing carbon monoxide oxidation with air oxygen

Chem Cent J. 2017 Mar 27;11(1):28. doi: 10.1186/s13065-017-0256-6.

Authors

Tatyana L Rakitskaya¹, Tatyana A Kiose², Kristina O Golubchik^{2

3}, Alim A Ennan³, Vitalia Y Volkova²

Affiliations

¹ Department of Inorganic Chemistry and Chemical Ecology, Odessa I.I. Mechnikov National University, 2, Dvoryanskaya St., Odessa, 65082, Ukraine. tlr@onu.edu.ua.
² Department of Inorganic Chemistry and Chemical Ecology, Odessa I.I. Mechnikov National University, 2, Dvoryanskaya St., Odessa, 65082, Ukraine.
³ Physicochemical Institute of Environment and Human Protection, 3, Preobrazhenskaya St., Odessa, 65082, Ukraine.

Abstract

Samples of natural clinoptilolite were modified by an acid-thermal method at nitric acid concentrations of 0.25, 0.5, 1.0, and 3.0 M and a contact time of 30 min. A series of catalysts, K₂PdCl₄-Cu(NO₃)₂-KBr/S (S = 0.25H-CLI, 0.5H-CLI, 1H-CLI, and 3H-CLI) was obtained. All samples were investigated by X-ray phase and thermogravimetric analysis, FT-IR spectroscopy, water vapor ad/desorption and pH metric method. Besides, K₂PdCl₄-Cu(NO₃)₂-KBr/S samples were tested in the reaction of low-temperature carbon monoxide oxidation. It have been found that, owing to special physicochemical and structural-adsorption properties of 3H-CLI, it promotes formation of the palladium-copper catalyst providing carbon monoxide oxidation at the steady-state mode down to CO concentrations lower than its maximum permissible concentration at air relative humidity varied within a wide range.

Keywords: Acid modification; CO oxidation; Clinoptilolite; DTG/DTA; FT-IR spectroscopy; Palladium–copper catalysts; Water vapor adsorption; XRD method.