Chemical Design of Binary TWC Catalysts for Conversion of NOx, CO and Hydrocarbons
A. M. BOLSHAKOV1, L. D. BOLSHAKOVA1, YU. N. SHCHEGOLKOV2, N. A. MAKAROV3 and O. V. SERGEEVA1
1Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences,
Leninskiy Pr. 29, Moscow 119991 (Russia) E-mail: bolsh@igic.ras.ru 2Central Research Geological Prospecting Institute of Non-Ferrous and Noble Metals (TsNIGRI),
Varshavskoye Shosse 129b, Moscow 117545 (Russia) 3Central Scientific Research Automobile and Automotive Engines Institute (NAMI),
Ul. Avtomotornaya 2, Moscow 125438 (Russia)
Pages: 737-742
Abstract
It has been found that thermal decomposition of binary complexes of composition [Co(NH3)5Cl][M*Cl4] (M*= Pt è Pd) and [M(NH3)x][M*Cly] (M= Cu, Ni) that have been obtained for the first time can be used to produce binary catalysts with uniform distribution of active components. The procedure of the controlled formation of multipurpose zones on the surface of Pt-Ni/g-Al2O3 and Pd-Co/g-Al2O3 catalysts has been developed, which significantly increases their activity. As a consequence of the study into the conversion of gas mixture on these catalysts, the possibility for segregative interaction of NO and CO has been found. It has been demonstrated that a non-additive increase in catalytic activity of binary catalysts is caused by oxygen depassivation of Pt and Pd centres owing to spillover of oxygen that is formed during NO decomposition. The mechanism of the spillover of oxygen has been suggested, the sense of which consists in the realization of a new reaction path of slightly bonded states of adsorbates.
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