Modified Pt-Fe catalysts for cinnamaldehyde hydrogenation
|Jacek A. Kijeński 1,2, Piotr Winiarek 1, Elżbieta Fedoryńska 1, Agata Purzycka 1|
1. Warsaw University of Technology, Faculty of Chemistry, Noakowskiego 3, Warszawa 00-664, Poland
A new method has been presented for the preparation of catalysts for selective hydrogenation of cinnamaldehyde to cinnamyl alcohol (compound used in the synthesis of drugs and flagrances). The following steps have been included in the catalysts preparation procedure: a. reaction of the support (g-Al2O3, TiO2, SiO2, MgO) with transition metal alkoxide (Zr(OBu)4, Ti(OBu)4, (BuO)3VO); b. thermal decomposition of the obtained surface complex; c. dry impregnation with an aqueous solution of Pt and Fe salts; d. drying; e. reduction with gaseous hydrogen. The products of each step were characterized by means of AAS, XRD, FTIR-PAS, SEM, SIMS and TPR. The monolayer of transition metal oxide (TMOM) (ZrO2, TiO2 or V2O5) has been formed on the surface of support as a result of surface complex decomposition (b.) at 623 K. Small crystallites (<10 nm) of these oxides have been observed after the decomposition of mentioned complex at 823 K. Ferroane phase (PtFe) has been detected among others on the surface of reduced Pt-Fe catalysts.
A hydrogenation of cinnamyl aldehyde was performed in the flow system (T = 423–573 K, p = 1 atm). The catalyst’s selectivity in cinnamyl alcohol synthesis increased in the following order: Pt/support << Pt-Fe/support < Pt/TMOM/support < Pt-Fe/TMOM/support. In the optimized reaction conditions hydrogenation of cinnamaldehyde over Pt-Fe/ZrO2/MgO yielded cinnamyl alcohol as a main product (78%, selectivity over 90 %).
Presentation: Keynote lecture at E-MRS Fall Meeting 2006, Symposium B, by Jacek A. Kijeński
See On-line Journal of E-MRS Fall Meeting 2006
Submitted: 2006-08-18 12:45 Revised: 2009-06-07 00:44
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