Role of ruthenium on the catalytic properties of CeZr and CeZrCo mixed oxides for glycerol steam reforming reaction toward H2 production

Abstract

Please cite this article in press as: L.M.M. T, et al., Role of ruthenium on the catalytic properties of CeZr and CeZrCo mixed oxides for glycerol steam reforming reaction toward H 2 production, Catal. Today (2014), http://dx. a b s t r a c tThe effect of ruthenium on the physico-chemical properties of CeZr and CeZrCo mixed oxides for H 2 production by glycerol steam reforming reaction has been studied. The combination of in situ Raman spectroscopy under both reductive and oxidative conditions, H 2 /O 2 pulses and XRD, Raman, BET analysis, H 2 -TPR and TPD-TPO analyses contributed to the determination of the structural and textural properties, redox behavior, re-oxidation capacity and resistance to carbon deposition of the synthesized catalysts. The results show that the catalytic activity is improved by the (positive) cooperative and complementary effect between cobalt and ruthenium that favors the selectivity toward the steam reforming, selective to H 2 , with respect to the unselective thermal decomposition of glycerol. Ruthenium stabilizes the cobalt cations inserted in the fluorite structure preventing its rejection as Co 3 O 4 ; and provides the necessary hydrogen to reduce Ce 4+ . The combination cobalt-ruthenium modifies positively the redox properties of the catalysts, increases the re-oxidation capacity (OSC) and promotes the gasification of the carbon deposits. Under the reaction conditions, the decrease in glycerol conversion came along with a change of selectivity. The formation of H 2 and CO 2 were strongly decreased, while the formation of CO, C 2 H 4 and condensable products (mainly hydroxyacetone) increase. The differences in the catalytic stability and activity of the catalysts are related to the capability of the catalysts to activate H 2 O under the reaction conditions, favoring the steam reforming reaction over the thermal decomposition.

Influence of Preparation Conditions on the Performance of Ni-Based Catalysts for Glycerol Steam Reforming

“…In GSR, the most investigated materials are Ni-, Pt-, Co-, and Ru-based catalysts, 14−17 and less researched materials are Rh-, Ir-, and Pd-based catalysts. 18−21 As a matter of fact, Ni-based catalysts are less costly and well-known to promote the rupture of C–C, O–H, and C–H bonds.…”

Unraveling the Structural and Compositional Peculiarities in CTAB-Templated CeO2-ZrO2-MnOx Catalysts for Soot and CO Oxidation

“…For Ce x Zr 1−x O 2 with 0.3 ≤ x ≤ 0.65, the formation of the most stable tetragonal phase was shown (see Ref. [37] and references within).…”

“…The spectrum for the binary oxide Ce 0.6 Zr 0.4 O 2 (Figure 4b) features the F 2g band and the broad weak bands at 300 and 612 cm −1 associated with the tetragonal substitution of oxygen atoms from the ideal fluorite lattice after the Zr introduction and the formation of oxygen vacancies, respectively [37,55].…”