稀土添加剂对镍转化催化剂性能的影响 Ⅳ.对甲烷裂解的影响

The effect of rare earth additives on the catalytic behavior of the nickel catalyst Ⅳ. Pyrolysis of methane

采用CH_4程序升温裂解技术考察了添加La_2O_3对Ni/α-Al_2O_3催化剂性能的影响。结果表明,La_2O_3能明显地提高催化剂对CH_4的裂解活性,Ni晶粒变小是其主要原因。热重分析表明,La_2O_3对Ni晶粒的覆盖使CH_4裂解表观活化能提高,炭形态分析表明,大量结炭以中空纤维形式存在。关键词:积炭,Ni催化剂。

The effect of La_2O_3 on Ni/α-Al_2O_3 catalytic behavior is investigated by the technique of temperature -programme pyrolysis of methane. It is found that La_2O_3 increases apparently the activity of Ni/ α-Al_2O_3 for CH_4 pyrolysis by reducing the size of nickel particles. TG analysis shows that the apparent activation energy for CH_4 pyrolysis is increased by closing nickel particles. The middle hollow-filamentous carbon is formed in the reaction.