SYNERGETIC EFFECTS OF PALLADIUM(II) AND COPPER(II) COMPOUNDS FIXED ON MODIFIED PHLOGOPITE IN THE REACTION WITH SULFUR DIOXIDE

Abstract

Palladium(II) and cuprum(II) compounds are the basic components of the Wacker-type heterogeneous catalyst for the low-temperature oxidation of carbon monoxide with oxygen. Al2O3, activated carbon and carbon fiber materials are most commonly used as a carrier. In search of new potential natural media, layered aluminosilicate – phlogopite as part of natural phlogopite concentrate was investigated and it was proved that copper-palladium catalysts are formed on acid-modified samples of phlogopite, which provide a high degree of conversion of carbon monoxide, which meets the sanitary and chemical norm of CO in the working area, namely CKCO ≤ 20 mg/m3. Regardless of the nature of the carrier, it was found that the catalytic effect is achieved due to the synergism of palladium(II) and copper(II). A typical situation is when carbon monoxide and sulfur dioxide are simultaneously present in the waste gases of industrial enterprises. In this regard, research on the polyfunctionality of the Pd(II)-Cu(II)/S̅ nanocatalyst is relevant. The kinetics of the interaction of sulfur dioxide with mono- and bimetallic compositions based on compounds of palladium(II), copper(II) and acid-modified natural (Phl) and thermally swollen (TS-Phl) phlogopite were studied. It was established that monometallic compositions М(ІІ)-KBr/X̅Н-TC-Phl-1, М(ІІ) = Cu(ІІ), Pd(ІІ) fixed on acid-modified samples of swollen phlogopite, except for 6Н-TS-Phl-1, do not show protective properties against sulfur dioxide. It has been proven that the bimetallic compositions Pd(II)-Cu(II)-KBr/S̅ (S̅ = 6H-Phl-1; X̅H-TS-Phl-1, X̅ = 1, 2, 3, 6 M HNO3) in the reaction with SO2 reveal a synergistic effect with a coefficient of КS >> 1, which leads to an increase in the time of the protective action of the samples and the amount of absorbed sulfur dioxide. The synergism constant depends on the conditions of acid modification of the carrier and has a maximum value in the case of the bimetallic composition fixed on the carrier 2Н-ТS-Phl-1.