General Acid-Type Catalysis in the Dehydrative Aromatization of Furans to Aromatics in H‑[Al]-BEA, H‑[Fe]-BEA, H‑[Ga]-BEA, and H-[B]-BEA Zeolites

Al, Ga, Fe, and B metal substituents have been examined for their ability to change the Brønsted acid strength of BEA zeolite and inhibit undesired hydrolysis in the production of aromatics from furan, 2-methylfuran, and 2,5-dimethylfuran. We employed electronic structure calculations to examine this series of furans in H-[Al]-, H-[Fe]-, H-[Ga]-, and H-[B]-BEA zeolites. These calculations were used to parametrize a microkinetic model to make direct comparisons to experiments run with furan and DMF in the weakest and strongest acid zeolites, H-[B]-BEA and H-[Al]-BEA, respectively. Electronic structure calculations revealed that the Diels–Alder reaction remains unaffected by changes to the Brønsted acid strength of the zeolite, whereas the dehydration and hydrolysis reactions are affected in a fashion reminiscent of general acid catalysis. Interestingly, despite its significantly lower acid strength, H-[B]-BEA was experimentally shown to have an activity similar to that of H-[Al]-BEA for the production of both benzene and <i>p</i>-xylene from furan and 2,5-dimethylfuran, respectively. Analysis with the microkinetic model revealed that, even with this weaker heterogeneous acid site, the dehydration reaction is sufficiently catalyzed, activating the aromatic production pathway. The use of a weaker, heterogeneous Brønsted-acidic zeolite did not have a significant effect on the product selectivity, however, indicating that the same reaction pathways are active with both catalysts

Tunable Oleo-Furan Surfactants by Acylation of Renewable Furans

An important advance in fluid surface control was the amphiphilic surfactant composed of coupled molecular structures (i.e., hydrophilic and hydrophobic) to reduce surface tension between two distinct fluid phases. However, implementation of simple surfactants has been hindered by the broad range of applications in water containing alkaline earth metals (i.e., hard water), which disrupt surfactant function and require extensive use of undesirable and expensive chelating additives. Here we show that sugar-derived furans can be linked with triglyceride-derived fatty acid chains via Friedel–Crafts acylation within single layer (SPP) zeolite catalysts. These alkylfuran surfactants independently suppress the effects of hard water while simultaneously permitting broad tunability of size, structure, and function, which can be optimized for superior capability for forming micelles and solubilizing in water