摘要
用稳定态活性测试法研究了一系列不同载钠量Ni/Al_2O_3催化剂上的CO_2加氢甲烷化行为,并对它们进行了XRD和程序升温还原表征。实验结果表明,在所用钠量范围内,于Ni/Al_2O_3上的CO_2加氢生成甲烷的活性随Na加入量的改变而变化,这与催化剂上Ni物种的分配有关,673K附近还原出的Ni物种可能是良好的CO_2加氢甲烷化活性中心。Na助剂的作用主要是改变Ni物种的分配。通过Na助剂的加入,可获得在化学剂量CO_2/H_2比下使CO_2几乎完全转化为甲烷的低镍催化剂。
Using a method of steady state activity test,hydrogenating methanation of CO2 was investigated over a series of Fi/Al2O3 catalysts promoted by Na of various addition amounts,and characterization of the catalysts were also carried out by XRD and temperature-programmed reduction. The results show that activity of Ni/Al2O3 over which CO2 is hydrogenated to methane changes with Na added within range,which is considered relative to the distributions of Ni species on the catalyst.It is found that the reduced Ni species near 673 K could be good active sites for hydrogenation of CO2 to methane. Substantially,Na promoter plays a role of changing distributions of Ni species on the catalyst. Adding Na, a catalyst with a lower content of niceki is obtained over which CO2 can be almost completely converted to methane at stoichiometric CO2 /H2.
出处
《天然气化工—C1化学与化工》
CAS
CSCD
北大核心
1994年第5期6-11,共6页
Natural Gas Chemical Industry
关键词
催化剂
钠
助剂
镍催化剂
二氧化碳
加氢
carbon dioxide, sodium promoter, nickel catalyst, methane, hydrogenation, methanation