Comparative adsorption and catalytic properties of CDSE-CDTE system components in carbon oxide (II) oxidation reaction

Abstract

Comparative adsorption and catalytic CdSe, CdTe and (CdSe)x(CdTe)1-x solid solutions properties are examined on the example of the CO and its participants-reactants (CO, O2) oxidation. Similarities and differences in their behavior are revealed. Adsorption and catalytic studies results full correspondence is shown. Individual and joint mechanisms of the CO catalytic oxidation reactants adsorption is proposed. The most active catalyst, CdTe, working effectively at ambient temperature, is discovered which allowes to recommend it for CO neutralization at greatly reduced energy costs.Adsorbtive catalysts were powders (Ssp = 0,405-0,91 m 2 /g) CdSe, CdTe and substitutional solid solutions (CdSe) x (CdTe) 1-x (x = 0,15; 0,25; 0,5; 0,75; 0,85 mol. % CdSe), obtained by isothermal diffusion in binary components mutual solubility areas [1].Adsorption was studied by volumetric, piezo-quartz microweighting (1,23⋅10 -11 g/(sm 2 Gts sensitivness to) with 258 -477 K temperature range and 6 -18 Pa pressure and IR-spectroscopy [2].Catalytic studies were performed on a flow-circulation installation [2, 3], which is directly connected to the analysis system with the same values of contact time and partial pressures of the reactants under conditions excluding mass and heat transfer processe effect: T = 290 -474 K, P = 101 308 Pa, carrier gas circulation rate = 22-24 ml/min, impulse volume = 5 ml. Direct catalytic studies were supplemented by indirect IR spectroscopy and FITR methods.Gas argon was mostly used as the carrier (for comparison with the air). Reactant gases (CO, O 2 ) were obtained according to well-known methods [4] followed by chromatographic analysis. The reaction mixture was prepared at a ratio of CO: O 2 = 1: 2. The initial CO content is (1,68-2,9) -5 mole.The specific catalytic activity was assessed by the specific rate at given temperatures and reaction mixture composition. The reaction course was judged by CO, O2 decrease and CO 2 increase which was determined chromatographically and with IR spectrophotometer method on "InfraLUM FT-02".