Effect the conditions of the acid–thermal modification of clinoptilolite have on the catalytic properties of palladium–copper complexes anchored on it in the reaction of carbon monoxide oxidation

Abstract

The dependence of the physicochemical and structural–adsorption properties of natural and acid–thermal modified clinoptilolite, and of Pd(II)–Cu(II) catalysts based on them, on the duration of acid–thermal modification is investigated. The samples under study are described via XRD and thermal gravimetric (DTG and DTA) analysis, IR, DR UV–Vis, EPR spectroscopy, and water vapor adsorption. Values of both the specific surface area (S_sp) and pH of aqueous suspensions are determined. The resulting catalysts are tested in the reaction of low-temperature carbon monoxide oxidation with air oxygen. A conclusion is drawn about the nature of surface bimetallic Pd(II)–Cu(II) complexes. The greatest catalytic activity is shown by complexes based on clinoptilolite and modified with 3 M HNO₃ for 0.5 and 1 h.