The Mechanism of Low-Temperature Oxidation of Carbon Monoxide by Oxygen over the PdCl2–CuCl2/γ-Al2O3 Nanocatalyst

摘要: The state of palladium and copper on the surface PdCl2–CuCl2/γ-Al2O3 nanocatalyst for low-temperature oxidation CO by molecular oxygen was studied various spectroscopic techniques. Using X-ray absorption spectroscopy (XAS), powder diffraction (XRD), diffuse reflectance infrared Fourier transform (DRIFTS), freshly prepared samples catalyst were studied. same also evaluated after interaction with CO, O2, H2O vapor in combinations. It shown that exists form Cu2Cl(OH)3 (paratacamite) nanophase catalyst. No palladium-containing crystalline phases identified. Palladium coordination initially is comprised four chlorine atoms. XAS this not capable oxidizing at room temperature absence O2 over 12 h. Copper(II) palladium(II) are reduced to Cu(I) Pd(I,0) species, respectively, presence (without O2). found DRIFTS both linear (2114 cm−1, 1990 cm−1) bridging (1928 forms coordinated formed upon adsorption onto surface. Moreover, formation CO2 detected oxygen. kinetics 18–38 °C an atmospheric pressure N2, (gas) mixtures a flow reactor (steady conditions).