A kind of metal-modified ZSM-5 molecular sieve catalyst and its preparation method and application

The present invention provides a kind of metal-modified ZSM-5 molecular sieve catalyst, which is characterized in that the catalyst is to be modified to be prepared to ZSM-5 molecular sieve by hydro-thermal method with modifying element；Wherein the modifying element is La and/or Ce；It is wherein in terms of 100% by the ZSM-5 gross mass in the ZSM-5 molecular sieve catalyst being prepared, the mass content of the modifying element is 0.01-15%；It is preferred that the metal-modified ZSM-5 molecular sieve catalyst prepares low-carbon alkene for lighter hydrocarbons catalytic pyrolysis, wherein it is preferred that the lighter hydrocarbons are the alkane that carbon atom number is 4-8 or alkene simple substance or mixture.Operation of the present invention is easy, without high-temperature operation, reduce energy consumption, improve the utilization rate of modifying element, modified effect is more preferable than traditional approach, reduces the additional amount of modifying element, improves catalyst to the selectivity of low-carbon alkene, the reaction service life is significantly strengthened in long period reaction, there is preferable application value.