Withthe large reserves of natural gas around the world, such as shale gas, methane hydrate, and biogas,research on how to utilize these alternative fuels has grown considerably. Currentindustrial-scaleprocesses for the conversion of natural gases to useful chemical feed stocks, which involves the conversion to syngasintermediates,arecomplex, inefficient, costly, and generatelarge quantities of CO2and coke byproducts.
The efficient conversion of these natural gas fuels will require a process wherein theC-H bond of methane isactivated, and the methane is selectively convertedto useful chemical products while minimizing dehydrogenation and over oxidation. Many methods have been developedfor the activation and conversion of methane with varying degrees of success, but thus far, none have been viable as industrial-scale processes.Theefficient activation and conversion of methane at the industrial-scale thus remains an importantchallenge in energy research.
A teamat Dalian Institute of Chemical Physicsled by Prof. Bao Xinhe has recently developed a promisingnew catalysisthat gives a high conversion rate ofmethane to ethylene, aromatics (benzene and naphthalene), and hydrogen under non-oxidative conditions. The results of theirwork werepresented in the May 9thissue ofScience. Through use ofanew catalyst, which consists of lattice-confined single iron sites embedded within a silicide matrix, methane isconverted tomethyl radicals. The methyl radicalsthen desorb from the surface and undergo a series of gas-phase reactions to form products. With this catalyst, a single pass conversion of methane reached 48.1%, and the total selectivity to ethylene and aromaticsexceeded 99%, with the selectivity to ethylene of 48.4%. This method developed by Bao et al. avoids the energy-intensive syngas generation of conventional natural gas processing. Furthermore, the method leads to little-to-no emission of CO2and coke.
