Steam reforming and oxidative steam reforming of methanol over CuO-CeO_2 catalysts

摘要

Steam reforming (SRM) and oxidative steam reforming of methanol (OSRM) were carried out over a series of coprecipitated CuO-CeO_2 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 O_2 concentration on catalytic activity were investigated. The activity of CuO-CeO_2 catalysts for SRM and OSRM increased with the copper content and 70 at.% CuO-CeO_2 catalyst showed the highest activity in the temperature range of 160-300 ℃ 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 Cu_2O, 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 O_2 into the feed stream, indicating that the partial oxidation of methanol (POM) is much faster than SRM. The optimum 70 at.% CuO-CeO_2 catalyst showed stable activities for both SRM and OSRM reactions at 300 ℃.