Electric field induced n-hexane cracking for selective production of light olefins over conductive zeolite-based catalysts

Electric field enables challenging chemical reactions to proceed efficiently under mild conditions. Herein, this external field was proposed to intensify cracking of alkanes for the production of light olefins, a typical reaction requiring high temperatures. Composite conductive materials were prepared by physically mixing anatase-type titanium dioxide (A-TiO 2 ) and HZSM-5. It was demonstrated that electric-assisted treatment induced significant microstructural changes of the composite catalyst. XPS and EPR revealed that Ti 4+ was converted into Ti 3+ , accompanied by oxygen vacancy formation, the amount of which increased with the applied power. H/D exchange experiments confirmed that electric field could induce “proton hopping”, increasing the amount of medium-strong Brønsted acid sites. DFT calculations and in situ infrared spectroscopy indicated that the electric field promoted the adsorption of n -hexane on the catalyst, accelerated the charge transfer between them. These synergistic effects facilitated n -hexane conversion while promoting monomolecular cracking pathway, favoring light olefins production. The light olefins yield reached 38.6 wt% over the optimal composite catalyst with the external heating at 400 °C and electric power of 6.5 W, surpassing the thermal cracking yields (6.6 wt% at 400 °C; 14.2 wt% at 450 °C). This study provides valuable insights into the efficient cracking of light alkanes under mild conditions and the application of zeolite in electrocatalysis.