Steam reforming and oxidative steam reforming of methanol over CuO–CeO2 catalysts

Steam reforming (SRM) and oxidative steam reforming of methanol (OSRM) were carried out over a series of coprecipitated CuO–CeO2 catalysts with varying copper content in the range of 30–80 at.% Cu (= 100 × Cu/(Cu + Ce)). The effects of copper content, reaction temperature and O2 concentration on catalytic activity were investigated. The activity of CuO–CeO2 catalysts for SRM and OSRM increased with the copper content and 70 at.% CuO–CeO2 catalyst showed the highest activity in the temperature range of 160–300 °C for both SRM and OSRM. After SRM or OSRM, the copper species in the catalysts observed by XRD were mainly metallic copper with small amount of CuO and Cu2O, an indication that metallic copper is an active species in the catalysis of both SRM and OSRM. It was observed that the methanol conversion increased considerably with the addition of O2 into the feed stream, indicating that the partial oxidation of methanol (POM) is much faster than SRM. The optimum 70 at.% CuO–CeO2 catalyst showed stable activities for both SRM and OSRM reactions at 300 °C.