Cu-ZrO_2-CeO_2/γ-Al_2O_3催化甲醇水蒸气重整制氢反应的性能

Performance of Cu-ZrO_2-CeO_2/γ-Al_2O_3 catalysts for hydrogen production from steam reforming of methanol

以γ-Al_2O_3为载体,采用浸渍法制备Cu-ZrO_2-CeO_2/γ-Al_2O_3催化剂,用XRD、N_2吸附-脱附、H_2-TPR、NH_3-TPD、CO_2-TPD等方法对其进行表征。在连续流动常压固定床微型反应器上评价Cu-ZrO_2-CeO_2/γ-Al_2O_3催化剂对甲醇水蒸气重整制氢反应的催化性能,考察了反应温度、水醇比和质量空速对催化性能的影响,反应结果表明Cu-ZrO_2-CeO_2/γ-Al_2O_3催化剂具有较高的催化活性和稳定性,在温度为260℃、水醇摩尔比为1.2∶1、质量空速为3.6h–1的条件下,甲醇的转化率可达99%以上,氢气的选择性为98%以上,一氧化碳的选择性低于2.5%。表征结果显示助剂CeO_2和ZrO_2的加入促进活性组分在载体表面的分散性,影响催化剂的孔结构和酸碱性,增强了催化剂的活性。

Cu-ZrO2-CeO2/γ-Al2O3 catalysts were prepared by the impregnation method using γ-Al2O3 as the support. The catalysts were characterized by means of XRD,N2 adsorption-desorption,H2-TPR,CO2-TPD,NH3-TPD and BET. Hydrogen production by the steam reforming of methanol over the Cu-ZrO2-CeO2/γ-Al2O3 catalyst was studied in a fixed bed micro-reactor. The effects of reaction temperature,mole ratio of H2O to methanol,WHSV on the catalytic performance and the stability of the catalysts were investigated. The experimental results showed that the methanol conversion rate reached 99%,the selectivity of hydrogen was 98%,while the selectivity of carbon monoxide was only 2.5% under the conditions of temperature 260℃,mole ratio of water to methanol of 1.2∶1,and WHSV of 3.6h^-1. Characterization results showed that the addition of CeO2 and ZrO2 promoted the dispersion of the active component on the surface of the carrier,affected the pore structure and acidity of the catalysts,and increased their activity.