Process for the conversion of hydrocarbons to olefins

A method for converting hydrocarbons in a hydrocarbon stream, the method comprising contacting the hydrocarbon stream with steam and a catalyst system under steam enhanced catalytic cracking conditions to produce an effluent comprising olefins, where:

• the catalyst system comprises a framework-substituted pentasil zeolite comprising from 0.2 to 1.0 wt. % Ce atoms and from 0.2 to 0.5 wt. % Fe atoms, as calculated on an oxide basis, based on the total mass of the framework-substituted pentasil zeolite;
• the framework-substituted pentasil zeolite has a modified pentasil framework, the modified pentasil framework comprising a pentasil aluminosilicate framework in which a portion of framework aluminum atoms of the pentasil aluminosilicate framework are substituted with Ce atoms and Fe atoms using solid state ion exchange;
• at least 80 mol. % of the Fe atoms are monomeric;
• and
• the steam enhanced catalytic cracking conditions comprise:
• a steam to hydrocarbon ratio of from 0.2 to 0.8;
• a reaction temperature from 450° C. to 750° C.;
• a reaction pressure from 1 bar to 5 bar;
• and
• a residence time from 0.5 seconds to 1000 seconds.