Hydrogen-rich gas generation from alcohols over cobalt-based catalysts for fuel cell feeding

The application of potassium promoted Co-ZnO-Al2O3 catalysts prepared by co-precipitation and citrate methods in the steam reforming of ethanol and methanol has been studied. Experimental results of catalytic activity and selectivity of catalysts are reported. The influence of preparation method, potassium addition (1 and 2 wt%) and the reaction temperature (350-600 °C) are the focus of the experimental studies. Potassium promoted catalysts prepared by the co-precipitation method with smaller cobalt active phase crystallites and with potassium deposited on the catalyst surface, are easier and in a higher extend reducible and are more active and selective in the steam reforming of ethanol and methanol than those with large crystallites prepared by the citrate method into which potassium was introduced with all other components. Also, the suppression of carbonaceous deposit formation was observed while potassium was present on the surface of the catalyst. It is found that steam reforming of both alcohols proceeds under comparable conditions and hydrogen yields are maximized in the temperature range of 420-450 °C. Cobalt-based catalysts can be used in the same processor for hydrogen generation from alternatively methanol or/and ethanol for fuel cell applications.