【摘要】 采用阴离子浸渍法制备了Au/Al2O3催化剂,考察了溶液pH值及浸泡处理对催化剂上CO氧化反应的影响.结果表明,催化剂的活性随着浸渍液氯金酸溶液pH值的升高而升高.对于经300℃下H2还原处理的Au/Al2O3催化剂,无论用水浸泡还是用氨水浸泡,室温下CO转化率均可达到100%,且催化剂具有良好的稳定性.用氨水浸泡的催化剂经氧化处理后依然保持高活性,但用水浸泡的催化剂活性大幅度下降.XPS结果表明,用氨水浸泡的Au/Al2O3催化剂表面含有Al,O,C,N,Na和Au原子,但没有Cl原子存在.这说明用氨水浸泡催化剂可有效除去Cl-离子而提高其催化活性.更多还原

【Abstract】 The Au/Al₂O₃ catalyst was prepared by anionic impregnation with HAuCl₄ solution.The effects of pH value of the solution and washing treatment on CO oxidation were studied.The CO oxidation reactivity at room temperature increased with the pH value of the solution.The catalyst reduced in H₂ at 300 ℃,whether steeping in H₂O or NH₃·H₂O,showed high activity and good stability.For the catalyst calcined in air at 300 ℃,steeping in NH₃·H₂O retained high activity but steeping in H₂O made the activity decrease rapidly.XPS was employed to determine the surface composition of the catalyst.The catalyst surface contained Al,O,C,N,Na and Au atoms.However,no Cl atoms were present on the surface of the catalyst steeped by NH₃·H₂O,indicating that the treatment could effectively eliminate Cl^-ions and improve the catalyst activity.更多还原