Europium Oxybromide Catalysts for Efficient Bromine Looping in Natural Gas Valorization

Europium Oxybromide Catalysts for Efficient Bromine Looping in Natural Gas Valorization

Vladimir Paunovic ́+, Ronghe Lin+, Matthias Scharfe, Amol P. Amrute, Sharon Mitchell, Roland Hauert, and Javier Pérez-Ramírez*

Angew. Chem. Int. Ed. 2017, 56, 9791-9795
http://onlinelibrary.wiley.com/doi/10.1002/anie.201704406/abstract

Abstract:
 

The industrialization of bromine-mediated natural gas upgrading is contingent on the ability to fully recycle hydrogen bromide (HBr), which is the end form of the halogen after the activation and coupling of the alkanes. Europium oxybromide (EuOBr) is introduced as a unique catalytic material to close the bromine loop via HBr oxidation, permitting low-temperature operation and long lifetimes with a stoichiometric feed (O2:HBr=0.25)—conditions at which any catalyst reported to date severely deactivates because of excessive bromination. Besides, EuOBr exhibits unparalleled selectivity to methyl bromide in methane oxybromination, which is an alternative route for bromine looping. This novel active phase is finely dispersed on appropriate carriers and scaled up to technical extrudates, enhancing the utilization of the europium phase while preserving the performance. This catalytic system paves the way for sustainable valorization of stranded natural gas via bromine chemistry.

Halogen-Mediated Conversion of Hydrocarbons to Commodities

 Halogen-Mediated Conversion of Hydrocarbons to Commodities

Lin, R.; Amrute, A. P.; Pérez-Ramírez, J. Chem. Rev. ASAP
http://pubs.acs.org/doi/pdf/10.1021/acs.chemrev.6b00551

Abstract:

Halogen chemistry plays a central role in the industrial manufacture of various important chemicals, pharmaceuticals, and polymers. It involves the reaction of halogens or halides with hydrocarbons, leading to intermediate compounds which are readily converted to valuable commodities. These transformations, predominantly mediated by heterogeneous catalysts, have long been successfully applied in the production of polymers. Recent discoveries of abundant conventional and unconven- tional natural gas reserves have revitalized strong interest in these processes as the most cost-effective gas-to-liquid technologies. This review provides an in-depth analysis of the fundamental understanding and applied relevance of halogen chemistry in polymer industries (polyvinyl chloride, polyurethanes, and polycarbonates) and in the activation of light hydrocarbons. The reactions of particular interest include halogenation and oxyhalogenation of alkanes and alkenes, dehydrogenation of alkanes, conversion of alkyl halides, and oxidation of hydrogen halides, with emphasis on the catalyst, reactor, and process design. Perspectives on the challenges and directions for future development in this exciting field are provided.

TOC: