【摘要】 采用吸附柱色谱新方法制备Au/Al2O3催化剂,并用于低温CO氧化反应,考察了Au盐溶液pH值及其与载体的液固比、载体比表面积和竞争吸附质等对Au催化剂性能的影响.结果表明,Au前驱体溶液的pH值为9,液固比为6,优先吸附丙酮制得的催化剂Au颗粒大小分布均匀,粒径为5nm左右,在-25oC即可实现CO完全转化.载体Al2O3比表面积对催化剂性能影响也较大.另外,优先加入的竞争吸附质的极性越低,所制催化剂上Au颗粒的分布越均匀.该法可提高Au利用率,有效去除有毒Cl-,为大规模制备Au催化剂提供了一条有效途径.更多还原

【Abstract】 A new method called adsorption column chromatography for the preparation of supported nano-gold catalysts was proposed.Au/Al2O3 was used as the model catalyst,and low-temperature CO oxidation was used as the model reaction.Effects of pH value of gold precursor solution,liquid-to-solid ratio of the gold precursor solution to the support,specific surface area of the support,and competition adsorbates such as water,ethanol,isopropanol,and acetone on the nano-structure of the gold catalyst were investigated.The optimal conditions are the pH value of gold precursor solution of 9,the liquid-to-solid ratio of 6:1,and acetone as the preferential adsorbate.Gold particles on the prepared Au/Al2O3 catalyst are well distributed and about 5 nm in diameter.The temperature for CO complete conversion is-25 oC.The specific surface area of Al2O3 has great impact on the Au/Al2O3 catalyst.The lower the polarity of the preferential adsorbate,the better the distribution of gold particles on the support.This method can improve the utilization ratio of gold and effectively remove toxic chlorine ions,and therefore it provides an effective way for the large-scale preparation of gold catalysts.更多还原