Steam reforming of ethanol over Co₃O₄-Fe ₂O₃ mixed oxides

Co₃O₄, Fe₂O₃ and a mixture of the two oxides Co-Fe (molar ratio of Co₃O₄/Fe ₂O₃ = 0.67 and atomic ratio of Co/Fe = 1) were prepared by the calcination of cobalt oxalate and/or iron oxalate salts at 500 C for 2 h in static air using water as a solvent/dispersing agent. The catalysts were studied in the steam reforming of ethanol to investigate the effect of the partial substitution of Co₃O₄ with Fe₂O ₃ on the catalytic behaviour. The reforming activity over Fe ₂O₃, while initially high, underwent fast deactivation. In comparison, over the Co-Fe catalyst both the H₂ yield and stability were higher than that found over the pure Co₃O₄ or Fe ₂O₃ catalysts. DRIFTS-MS studies under the reaction feed highlighted that the Co-Fe catalyst had increased amounts of adsorbed OH/water; similar to Fe₂O₃. Increasing the amount of reactive species (water/OH species) adsorbed on the Co-Fe catalyst surface is proposed to facilitate the steam reforming reaction rather than decomposition reactions reducing by-product formation and providing a higher H₂ yield. ©