Abstract:
Hydrogen production by the steam reforming of methanol (SRM) has been investigated over Au/ZnO and Au/ZnO -Fe2O3 catalysts in the temperature range of 250-450°C. Both catalysts were prepared by a deposition-precipitation method and were characterized by TEM, XRD, TPR, and TPO techniques. The XRD analysis confirms the desired structure and phase purity of ZnO, Fe2O3, and ZnFe204, and the presence of gold in the prepared samples. TEM observations show that the particle sizes of the gold are smaller than 5 nm for all catalysts except for the 5% atom Au/ZnO calcined at 500°C. For the activity tests, the results show that the catalytic performance of the Au/ZnO -Fe2O3 is higher than that of the Au/ZnO at low temperature range. A maximum methanol conversion of 95.58% was achieved with 5% atom Au/ZnO calcined at 400°C for 4 hours and pretreated with hydrogen, while 5% atom Au/ZnO-Fe203 with a 9:1 molar ratio of ZnO to Fe2O3 calcined at 200°C for 4 hours and pretreated with oxygen gave 100% methanol conversion. In addition, no deactivation was observed during 24 hours of testing for both catalysts.
