B2O3对CoO-MoO3/CeO2-Al2O3催化剂耐硫甲烷化性能的影响

摘要

采用等体积浸渍法制备不同B2O3负载量的xB-CoMo/CeAl系列催化剂,研究不同B2O3负载量对催化剂耐硫甲烷化性能和催化剂结构的影响.采用N2吸附-脱附、XRD、H2-TPR、NH3-TPD及Raman等方法对催化剂进行表征.实验结果表明,B2O3的加入一定程度上提高CH4的选择性,降低C2H6的选择性,降低CO的转化率.表征结果显示,B2O3不利于催化剂活性组分的分散且生成低反应活性的CoMoS(Ⅱ)结构及没有甲烷化活性Co9S8物种,从而导致反应活性降低.%xB-CoMo/CeAl catalysts with different boron loading were prepared through impregnation with H3BO3 solution,and were characterized by means of BET,XRD,NH3-TPD,H2-TPR and Raman. The catalysts were used in sulfur-resistant methanation. The effects of boron content on the structure and performances of the catalysts were investigated. The results showed that the addition of B2O3 to CoO-MoO3/CeO2-Al2O3 could improve the selectivity to CH4,but reduce the selectivity to ethane and the conversion of CO. It was indicated that the addition of B2O3 was unfavorable to the dispersion of the active component molybdenum oxide and led to the formation of Co9S8 and CoMoS(Ⅱ),which could reduce the activity of the catalysts.