还原条件对氧化钼基催化剂结构及性能的影响

Effects of Reduction Conditions on the Structure and Behaviors of Catalysts Supported on the Molybdenum Oxides

在常压连续流动固定床反应器上,考察了还原时间和还原温度对MoO;和5%Ni-MoO_x两种催化剂上正庚烷异构化反应催化活性的影响。结果表明,在还原时间6h,还原温度623 K条件下,两种催化剂对正庚烷异构化的催化活性最大,MoO_x催化剂对正庚烷的转化率达40.1%,5%Ni-MoO_x催化剂对正庚烷的的转化率达43.5%;两种催化剂对正庚烷的异构化选择性均达到85%以上。在相同还原条件下,对两种催化剂催化性能进行了比较,结果发现,还原反应时间越短,还原温度越低,两种催化剂对正庚烷异构化反应活性的差别就越明显,表明Ni组分的加入促进了MoO_x的还原,在一定程度上使还原态MoO_x的催化性能得到了改善。

The effects of reduction time and reduction temperature on the catalytic activity for isomerization of n - heptane over the two kinds of catalysts including MoOx and 5% Ni - MoOx in the continuous fix - bed reactor. The result showed that the above two catalysts had the best catalytic activity for isomerization of n - heptane with the conversion of n - heptane 40.1% and 43.5 % for MoOx and 5 % Ni - MoOx respectively and the selectivity for n - heptane isomerization over 85 % at 623 K in 6 hours of reduction time. The two catalysts were compared on the catalytic activity under the difference of catalytic activity between the two catalysts same reduction conditions. The result showed that the was more obvious when reduction time was shorter and the reduction temperature was lower,which suggesting the addition of Ni component improved the reduction of MoOx thus impoved the catalytic behaviors of MoOx in the reduction state to some extent.