Effect of Carrier Phase Conversions on the Thermal Stability of Alumina Catalysts with Low Palladium Content
R. M. KENZHIN1, A. A. VEDYAGIN1,2, A. M. VOLODIN1, V. O. STOYANOVSKIY1, E. M. SLAVINSKAYA1, P. E. PLYUSNIN3, YU. V. SHUBIN3, and I. V. MISHAKOV1,2
1Boreskov Institute of Catalysis, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
2Tomsk Polytechnic University, Tomsk, Russia
3Nikolaev Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
Keywords: alumina, palladium, decontamination, phase transformations, stability
Pages: 25-33
Abstract
The present work is devoted to comparative analysis of the activity and stability of low-percentage palladium catalysts under conditions of three-route catalysis (CO and hydrocarbons oxidation, and nitrogen oxides reduction). Gamma alumina and delta alumina were used as carriers. Catalysts containing 0.12 % Pd and δ-Al2O3 on γ-Al2O3 and δ-Al2O3 were prepared by the wetness impregnation method. The resulting samples were studied by a set of physicochemical method. The forced thermal ageing method was used to assess the stability of catalysts to deactivation processes of the active component of Pd. Ethane hydrogenolysis allowed assessing the dispersion degree of the active component. The highly sensitive methods of electron spin resonance (ESR) and electron spectroscopy of diffuse reflectance (ESDR) were used to study the state of deposited palladium. Testing of the catalytic activity of samples under conditions of three-route catalysis was carried out. As a result, it was demonstrated that phase conversions of an alumina carrier did not exert significant effects on the thermal stability of samples during catalytic reactions.
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