(21f) Supported Cobalt Catalysts for Ethanol Steam Reforming by Impregnation and Coprecipitation Methods

Hydrogen production was carried out via ethanol steam reforming over supported cobalt catalysts prepared by impregnation and coprecipitation methods. Commercial CeZrO4 with high surface area was used to support 10 wt % cobalt in the impregnation method. It was found that 10 wt % Co/CeZrO4 is an efficient catalyst to achieve ethanol conversion of 100% and hydrogen yield of 82% (4.9 mol H2/ mol ethanol converted) at 450 oC. When Co/CeZrO4 catalysts prepared by coprecipitation in the same composition as by impregnation, their surface area and morphology were found pH dependent, which result in different catalytic activity and selectivity toward the ethanol steam reforming.

In this study, in situ X-ray diffraction (XRD) was used to investigate the crystallographic evolution of Co/CeZrO4 in various reduction processes. Surface morphology was characterized by transmission electron microscopy (TEM). In addition, in situ infrared spectroscopy (DRIFTS) was used to study the surface chemistry of catalysts prepared from impregnation and coprecipitation methods in ethanol steam reforming.