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Abstract: Whereas the hegemony of the Fischer–Tropsch synthesis is well established for the valorization of methane in the case of important gas fields, the methane dehydro-aromatization reaction remains an interesting solution to convert methane obtained as by-product of oil extraction and thus fight against flaring and global warming. Until now, it was generally accepted that the molybdenum is anchored on the Brønsted acid sites of the zeolite as (Mo2O5)2+ species. The molybdenum performs the dehydrogenation and coupling of CH4 to ethylene which is consecutively oligomerized to benzene over the Brønsted acid sites. In the present work, we bring evidence that this picture is actually more complicated than it seems. The Si/Al ratio of the zeolite, and consequently the density of available Brønsted acid sites, plays a dramatic role on the anchoring mode of the molybdenum and on its catalytic activity. [Copyright &y& Elsevier]

Abstract: Binderless beta zeolite has been anchored on a silicon carbide foam with a monolithic shape. The catalytic activity of the resulting composite was evaluated for a Friedel–Crafts reaction carried out in a fixed-bed configuration: the benzoylation of anisole to p-methoxybenzophenone. The results obtained were compared with those of a commercial beta zeolite. Significantly higher product yields along with a stable activity were obtained with the BEA/SiC composite. It has been suggested that the opened structure of the β-SiC foam and the absence of any binder allow a fast desorption of the p-ketone which is the main product of the reaction but also the major source of deactivation due to strong adsorption and/or coke formation inside the microporosity of the zeolite. [Copyright &y& Elsevier]