Catalytic behavior toward oxidative steam reforming of dimethyl ether over CuFe 2O 4-Al 2O 3 composite catalysts

Abstract

Oxidative steam reforming of dimethyl ether (DME OSR) for hydrogen production was studied over CuFe 2O 4-Al 2O 3 composite catalysts. The catalytic behaviors of the catalysts were investigated in terms of DME conversion, H 2 production rate, and selectivity to CO 2, CO, and CH 4 as well as the catalyst temperature and gaseous concentration profiles along the catalyst bed. The catalysts exhibited good reforming activity and low CO formation (<2.5 vol.%) with trace amounts of other byproducts in the temperature range of 275–375 °C, steam/DME of 2.5, and O 2/DME of 0–1. The increase in O 2/DME resulted in improved DME conversion, but lower selectivity to H 2. The catalyst was essentially stable in DME OSR in the 200 h stability test in the temperature range of 317–335 °C, while H 2 concentration was stably obtained at ca. 62 vol.%. Oxygen was rapidly consumed in the beginning zone of the catalyst bed where the exothermic partial oxidation of DME along with CO oxidation would preferentially occur. The majority of reactions in the remaining zone was endothermic steam reforming of DME together with water gas shift reaction.