Intensification and deactivation of Sn-beta investigated in the continuous regime $(document).ready(function() { if (!$("html").hasClass("ie8")) { $.ajax({ url: "https://crossmark-cdn.crossref.org/widget/v2.0/widget.js", dataType: "script", cache: true }).done(function() { $(".crossmark-button").addClass("visible"); }); } });

Abstract

Despite a proliferation of research focusing on the synthesis and catalytic chemistry of Sn-containing zeolite beta, research focusing on its intensification lacks behind, prohibiting its further exploitation. In this manuscript, we investigate and optimise the continuous flow activity of Sn-β for a range of sustainable chemical transformations, including the transfer hydrogenation of model and bio-renewable substrates (furfural), and the isomerisation of glucose to fructose. Extended time-on-stream studies reveal Sn-β to be a very stable catalyst during continuous operation in an organic solvent. Spectroscopic methodologies reveal that deactivation in these cases is related to fouling of the micropores with the product and higher molecular weight carbonaceous residue. Periodic regeneration by heat treatment is found to restore full activity, allowing Sn-β to be used for over 700 h continuously with no greater than 20% loss in activity. In contrast, operation in an aqueous medium is extremely disadvantageous, as it causes total destruction of the catalyst and permanent deactivation. In these cases, however, long term activity can still be achieved by modifying the solvent chosen for reaction, with methanol appearing to be a suitable alternative. The promising results presented herein conclusively demonstrate the potential of Sn-β to operate as an industrial heterogeneous catalyst.