Li掺杂对LaNi/Al_2O_3在焦油重整中催化性能的影响

Effect of Li Doping on Catalytic Performance of LaNi/Al_2O_3 in Tar Reforming

采用浸渍法制备了LiLaNi/Al2O3催化剂,并用XRD,SEM,TPR等对其进行了表征.Li的加入对催化剂的结构、NiAl2O4的结晶度及Ni2+离子还原能力都有较大影响.以甲苯为焦油的模型化合物,在固定床反应器中对高温焦炉煤气中焦油催化转化反应进行了评价.结果显示,Li能显著改善LaNi/Al2O3催化剂的催化反应活性,提高产物中H2的含量.在750℃、水/碳比为2.0的条件下,含0.5%(ω)Li的LiLaNi/Al2O3催化剂能将甲苯完全转化为小分子气体,产物中H2含量显著增加.

The catalytic activity of LiLaNi/Al2O3 was evaluated in a fixed-bed reactor via steam reforming of toluene as a model tar compound. The results showed that addition of Li could improve the catalytic activity of LiLaNi/Al2O3 and enhance H2 content in the resultant gas mixture. XRD, SEM and TPR results illustrated that the addition of Li had great influence on the structure of LiLaNi/Al2O3 catalysts and the reduction ability of Ni^2＋ ions. The catalyst 0.5LiLaNi/Al2O3 possessed the optimal catalytic performance. LiLaNi/Al2O3 also showed good resistance to coking for steam reforming of tar at a high temperature of 750 ℃.