Oxidative steam reforming of methanol on Ce 0.9Cu 0.1O Y catalysts prepared by deposition–precipitation, coprecipitation, and complexation–combustion methods

Abstract

The production of hydrogen from oxidative steam reforming of methanol has been tested for Ce 0.9Cu 0.1O Y catalysts. The catalysts were prepared by deposition–precipitation (dp), coprecipitation (cp), and complexation–combustion (cc) methods. These catalysts were characterized using BET, TEM, X-ray diffraction (XRD), and Raman spectroscopy. A solid solution was formed in the Ce 0.9Cu 0.1O Y prepared by complexation–combustion. The incorporation of Cu atoms into CeO 2 lattice leads to an increase of oxygen vacancy. XPS results indicated that the Cu + is the main Cu species for the Ce 0.9Cu 0.1O Y -cc sample and the synergistic function between Cu 2+/Cu + and Ce 4+/Ce 3+ occurred in the redox cycle, which is the reason for lower reduction temperatures and improved redox properties as shown in TPR profiles. In the case of the Ce 0.9Cu 0.1O Y -cp and Ce 0.9Cu 0.1O Y -dp samples, most CuO dispersed on the CeO 2; the poor interaction between CuO and CeO 2 does not affect redox properties of CeO 2. Methanol conversions higher than 85% with 90% hydrogen yield were obtained for Ce 0.9Cu 0.1O Y -cc from the oxidative steam reforming of methanol at 240 °C. However, the catalysts prepared by coprecipitation and the deposition–precipitation method showed methanol conversion lower than 30% at 240 °C, and less than 60% even at 360 °C. The high catalytic activity of Ce 0.9Cu 0.1O Y -cc is mainly related to the formation of solid solution and the improved redox properties.