Inspired by the peers' work above, olefin is another kind of alkylation agent even display lower alkylation barrier compared with methanol . Olefins alkylation with aromatics is called Friedel-Crafts reaction . Normally, olefins were regarded as adsorption and activation on acid sites of zeolites, then protonated carbocation attack benzene ring forming alkylated aromatics . Over the iron-based catalysts, CO2 and H2 can be converted to CO and water by the reverse water gas shift reaction (RWGS) on Fe3O4 active sites, then CO and H2 could be converted to lower olefins consecutively through Fischer Tropsch synthesis (FTS) on FexCy active sites . Besides, Fischer Tropsch synthesis route present higher activity compared with the methanol route using metal oxide as active catalyst . By incorporating structural promoter and alkali promoters to improve the dispersion and modulate the electronic property of the active phase to promote the desorption of the olefin desorption respectively, the olefin selectivity could be improved .