Hydrogen production from dimethyl ether steam reforming over composite catalysts of copper ferrite spinel and alumina

摘要

Dimethyl ether steam reforming (DME SR) was performed over composite catalysts of copper ferrite spinel (CuFe2O4) and alumina for hydrogen production, applicable to fuel cell. A highly active composite was achieved when the calcination temperature of the Cu spinel was at 900 degrees C and that of the alumina was at or below 700 degrees C. The calcination temperature strongly affected the crystallinity and reducibility of the copper ferrite spinel and the acidity of alumina. The composite catalysts both with and without pre-reduction were active for DME SR when the pre-reduced catalyst exhibited higher initial activity, but longer activation process was observed for the composite catalyst without pre-reduction. DME conversion and hydrogen production significantly depended on gas hourly space velocity (GHSV) and reforming temperatures (T-r). DME conversion (> 95%), H-2 production rate (similar to 50 mol kg(cat)(-1) h(-1)), and H-2 concentration (ca. 73%) were achieved at T-r of 350 degrees C and GHSV of 1500 h(-1). The maximum H-2 production rate of 120 mol kg(cat)(-1) h(-1) was found at T-r of 450 degrees C and GHSV of 4000 h(-1). Mixing state of the copper spinel and the alumina was also investigated. After mixing with alumina, the present CuFe2O4 markedly exhibited excellent activity for DME SR in comparison to the commercial CuFe2O4 and Cu/ZnO/Al2O3. (c) 2007 Elsevier B.V. All rights reserved.