Influence of palladium precursors on methanol synthesis from CO hydrogenation over Pd/CeO_2 catalysts prepared by deposition-precipitation method

摘要

The impact of palladium precursors on the catalytic behavior of Pd/CeO_2 catalysts was studied for methanol synthesis through hydrogenation of carbon monoxide. Catalysts prepared from palladium chloride and palladium acetate showed much higher overall catalytic activities than those prepared using palladium nitrate. Palladium precursors did not have a significant influence on the distribution of products, very similar selectivities of methanol and methane were obtained. The palladium precursor, or more specifically its anion, had an effect on the final palladium particles, and therefore affected the interaction between Pd and ceria, which would cause different reaction results. The catalytic deactivation with time-on-stream was interpreted in terms of the growth of Pd particles under reaction conditions.