低温深度脱除液相丙烯中微量CO负载型催化剂的研究

Study on supported catalyst for removal trace amount of CO in propylene at low temperature

以廉价的拟薄水铝石为原料,采用等体积浸渍法,制备负载型CuO-MOx-CeO_2/γ-Al_2O_3催化剂,通过XRD、N2-吸附脱附、H_2-TPR、CO-TPD等表征,考察了载体焙烧温度、助剂改性(Co、Zn、Fe、Zr)及组分相互作用对CO脱除性能的影响。结果表明,拟薄水铝石经400~800℃焙烧后为γ-Al_2O_3晶相,随着焙烧温度的升高,孔径分布集中度降低,逐渐向中孔方向移动,750℃焙烧制得样品的还原性能最优,CO催化活性最高;添加过渡金属助剂,Co有利于催化剂还原性能和CO吸附性能提高,CuO、CeO_2、Co_3O_4组分间的相互协同作用,共同促进了CO催化氧化性能的提高。优化得到的CuO-Co_3O_4-CeO_2/γ-Al_2O_3催化剂,在30℃、3.0MPa的工况条件下,可将液相丙烯中的CO含量由10.0×10^(-6)脱除低至9.0×10^(-8),连续反应1500min,稳定性良好,具有较好的工业应用前景。

Taking pseudoboehmite as raw material,CuO-CeO_2/ γ-Al_2O_3 catalysts were prepared by the impregnation method and used for CO catalytic oxidation. XRD,N_2-physisorption,H_2-TPR and CO-TPD have been used to elucidate the effect of supports calcination temperature,transition metals modification（ Co,Zn,Fe,Zr） and components interaction on the catalytic performance. Results show that when calcination temperature is in the range of 400 ~ 800 ℃,the obtained samples are γ-Al_2O_3. With the increase of the calcination temperature,the concentration of pore size distribution decreased and gradually moved to the mesopore. CuO-CeO_2/ γ-Al_2O_3 catalyst,γ-Al_2O_3 calcined at 750 ℃,exhibits the best reduction and catalytic performance in the CO catalytic oxidation. Co-doped CuO-CeO_2/ γ-Al_2O_3 catalyst,the reduction and CO adsorption performance have been improved,the synergistic effect among CuO,Co_3O_4 and CeO_2 could improve the catalyst activity. Under the conditions of 30 ℃ and 3. 0 MPa,over CuO-Co_3O_4-CeO_2/ γ-Al_2O_3 catalyst,CO in the liquid propylene could be removed from 10. 0 × 10- 6to 9. 0 × 10- 8for 1 500 min. This catalyst has good prospects for industrial application.