Production of Hydrogen by Partial Oxidation of Methanol Over ZnO-Promoted Copper Catalysts Supported on Rice Husk Ash

ZnO-promoted copper catalysts supported on rice husk ash (Cu/ZnO/RHA) have been tested for partial oxidation of methanol (POM) to produce hydrogen. The catalysts were prepared by deposition precipitation method and characterized by XRD, TPR, and H-2-N2O titration techniques. A detailed study on the catalytic activity of the Cu/ZnO/RHA catalysts was performed to optimize the amount of ZnO promoter, pH, calcination temperature and reaction temperature. The catalytic activity of Cu/ZnO/RHA catalysts was compared with that of Cu/ZnO/SiO2 catalysts in order to understand the feasibility of employing rice husk ash as support materials. The results showed that the improved activity and selectivity were mainly due to the enhanced copper surface area and copper dispersion. However, the stabilization effect of ZnO also played an important role in catalytic activity. The CH3OH conversion and H-2 selectivity were increased with increases in temperature from 473 to 573 K. Beyond 523 K, the CO selectivity was significant. A comparison between Cu/ZnO/RHA and Cu/ZnO/SiO2 catalysts proves that Cu/ZnO/RHA is an active and selective catalyst with good stability compared to the silica supported catalyst.