Methyl bromide is used as feed in a process that converts it to gasoline. It is prepared by the gas-phase reaction of CH4 with Br2, a reaction that produces, besides the desired CH3Br, large amounts of CH2Br2. The latter cokes the catalyst used for gasoline production. The separation of CH2Br2 by distillation makes gasoline production too expensive. It is therefore important to increase the selectivity of the bromination reaction. We show that a small amount of I 2 catalyzes the reaction CH2Br2 + CH 4 → 2CH3Br, which leads to higher CH4 conversion and higher selectivity to CH3Br. These findings are promising for developing a low-cost integrated bromine-iodine based dual-halogen pathway to convert stranded natural gas into fuels and chemicals. © 2013 American Chemical Society.

Oxidative dehydrogenation is a promising way to produce olefins, diolefins and aromatics. However, the product yield is limited by the consecutive oxidation of the product to oxygenated products. The highest yield reported for propane oxidative dehydrogenation is only about 30%. Alternatively, halogens can be used as oxidants in oxidative dehydrogenations. Although the iodine process is highly selective, it requires very high reaction temperatures (≈900K) to give a good yield of C3H6+C3H7I, and iodine is too expensive for industrial deployment. Bromine is a more reactive oxidant but less selective towards C3H6 and C3H7Br. We show that the use of bromine-iodine mixtures with low iodine content (no greater than 20%) results in up to 80% of C3H6+C3H7X single-pass yield at moderate reaction temperatures (<800K). The results are promising for developing a low temperature on-purpose propylene technology. Furthermore, the underlying chemistry might be extended to the synthesis of many other commercially desirable unsaturated hydrocarbons. © 2013 WILEY-VCH Verlag GmbH & Co.

We describe a general approach for the synthesis of micro-/nanostructured metal chalcogenides from elemental precursors. The excellent solubility of sulfur, selenium, and tellurium in phosphonium ionic liquids promotes fast reactions between chalcogens and various metal powders upon microwave heating, giving crystalline products. This approach is green, universal, and scalable.

Zeolites are crystalline inorganic solids with microporous structures, having widespread applications in the fields of catalysis, separation, adsorption, microelectronics, and medical diagnosis. A major drawback of zeolites is the mass transfer limitation due to the small size of the micropores (less than 1 nm). Numerous efforts have been dedicated to integrating mesopores with the microporous zeolite structures by using templating and/or destructive approaches. Here we provide a new strategy for hierarchical pore size zeolite synthesis, without using supramolecular or hard templates. The branching epitaxial growth behavior, as a result of aluminum-zoning, contributes to the formation of the hierarchical porous zeolite structures.