Pt based bimetallic catalysts prepared by conventional impregnation and deposition and reduction in liquid phase methods for selective hydrogenation of citral

DE MIGUEL, S.; RODRIGUEZ, V. ; SCELZA, O.; STASSI, J.; VILELLA, J.; ZGOLICZ, P.

Kazan

Congreso; 12th European Congress on Catalysis - EuropaCat-XII; 2015

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In the fine chemical industry, supported bimetallic catalysts are frequently used, because such systems exhibit interesting yields with regard to their applications. An important example of application is the selective hydrogenation of the carbonyl group (C=O) of alpha,beta-unsaturated aldehydes into alpha,beta-unsaturated alcohols (UA) [1]. However, the challenge in the development of bimetallic catalysts for this type of reaction is to achieve the hydrogenation of the C=O without affecting the C=C olefinic bond, since, the hydrogenation of the C=C is thermodynamically more favorable than the hydrogenation of the C=O, and usually, low yields are obtained with typical monometallic catalysts of hydrogenation [1,2]. In this sense, bimetallic nanoparticles allow a better tailoring of the electronic and catalytic properties. The final selectivity of these bimetallic nanoparticles depends both on the second metal/noble metal ratio and the interaction between the active metal and the reduced or ionic species of the second metal, which act as Lewis acid sites to promote the hydrogenation of the carbonyl group [1]. However, both the interaction between the metals and the type of promoter species formed strongly depend on the nature of the support and the preparation method. In this work, Pt-based bimetallic catalysts multi-walled carbon nanotubes-supported were prepared by two methods (conventional impregnation followed of a reduction step in H2 flow (CI) and deposition-reduction in liquid phase (RLP)) in order to study and compare their performances in the citral hydrogenation.