Hydrogen production by steam reforming of ethanol over Co sub(3)O sub(4)/La sub(2)O sub(3)/CeO sub(2) catalysts synthesized by one-step polymerization method

Catalysts composed of Co sub(3)O sub(4)/La sub(2)O sub(3)/CeO sub(2) mixtures were synthesized by the one-step polymerization method, with the three precursors of catalysts mixed together in a single step before the polymerization step. The catalysts were characterized by X-ray diffraction (XRD), temperature-programmed reduction (H sub(2)-TPR), physisorption of N sub(2) (BET), X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectroscopy (EDX), scanning electron microcopy (SEM), and then were tested in the steam reforming of ethanol (SRE, molar ratio = 3H sub(2)0:1ethanol) at 500 [degrees]C for 6 h. The mixture of the three oxides led to the formation of the Ce(La)O sub(x) solid solution which was characterized by XRD, TPR and XPS. Even the three precursors of the catalysts (La, Ce and Co) were mixed together by the polymerization method, the results indicated that the La sub(2)O sub(3) has a very noticeable preference to interact with CeO sub(2) rather than with Co sub(3)O sub(4). The catalysts composed of the mixture of the three oxides (Co sub(3)O sub(4)/La sub(2 )O sub(3)/CeO sub(2)) performed better in the catalysis than those catalysts containing only two oxides (Co sub(3)O sub(4)/CeO sub( 2) or Co sub(3)O sub(4)/La sub(2)O sub(3)). The increase in concentration of the Ce(La)O sub(x) solid solution in the cobalt catalysts, increased the selectivity to H sub(2) and CO sub(2), decreased the carbon deposition rates during the SRE, and hindered the formation of graphitic carbon. The best performance in the catalysis was reported by the sample containing 12 mol% of La sub(2)O sub(3) in the mixture (CoCe sub(12) La sample), which is promising for SRE.