Plasma-Assisted Catalytic Effects of TiO₂/Macroporous SiO₂ on the Synthesis of Light Hydrocarbons from Methane

Valuable light hydrocarbons such as ethane, propane, butane and corresponding olefins were successfully synthesized using a plasma-assisted catalytic system. The catalytic activity of titania nanoparticles seemed to selectively increase the conversion of intermediates into longer C₅₊ hydrocarbons, while suppressing the dehydrogenation of intermediates to coke. In addition, DFT calculations revealed that the intermediate hydrocarbon radicals on titania active sites seemed to prefer to form longer hydrocarbons rather than coke in terms of dehydrogenation energy and relative adsorption energy. In addition, the proper selection of support material in terms of dielectric constant, particle size, and pore size could greatly improve the selectivity toward saturated light hydrocarbons. The fraction of saturated hydrocarbons in C₂–C₄ was measured over 80 %. By adopting macroporous silica with a large pore size, the required bed weight was appreciably reduced, without compromising performance.