The effect of the ternary component on the structure and catalytic behavior ofCu/ZnO/MxOy catalysts for methanol synthesis from hydrogenation and carbon di0xide hasbeen studied by EXAFS. The results show that there is a relationship among the catalyticactivity, the acidity of the ternary component and the dispersity of Cu respectively. It meansthat the active site of the catalyst of this reaction should be Cu or Cu+.
We demonstrate for the first time that a short time of microwave irradiation on the oxide precursor of a Cu/ZnO/Al2O3 catalyst can provide unique opportunity for tailoring the microstructure and activity of the catalyst for methanol steam reforming. It is shown by in situ XRD that a considerable increase in the microstrain of Cu nanocrystals could be achieved in the catalysts processed by microwave irradiation for 310 min, which correlates well with the enhanced CH3OH conversion as observed on the corresponding samples. The present work also confirms that although the high specific surface area of Cu is a prerequisite for catalytic activity, it does not account for the observed changes in activity and selectivity alone without taking bulk microstructural changes into account.
