Solid base catalysed 5-HMF oxidation to 2,5-FDCA over Au/hydrotalcites:fact or fiction?

Ardemani, Leandro; Cibin, Giannantonio; Dent, Andrew J.; Isaacs, Mark A.; Kyriakou, Georgios; Lee, Adam F.; Parlett, Christopher M.A.; Parry, Stephen A. and Wilson, Karen (2015). Solid base catalysed 5-HMF oxidation to 2,5-FDCA over Au/hydrotalcites:fact or fiction? Chemical Science, 6 (8), pp. 4940-4945.

Abstract

Nanoparticulate gold has emerged as a promising catalyst for diverse mild and efficient selective aerobic oxidations. However, the mechanism of such atom-economical transformations, and synergy with functional supports, remains poorly understood. Alkali-free Mg-Al hydrotalcites are excellent solid base catalysts for the aerobic oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furan dicarboxylic acid (FDCA), but only in concert with high concentrations of metallic gold nanoparticles. In the absence of soluble base, competitive adsorption between strongly-bound HMF and reactively-formed oxidation intermediates site-blocks gold. Aqueous NaOH dramatically promotes solution phase HMF activation, liberating free gold sites able to activate the alcohol function within the metastable 5-hydroxymethyl-2-furancarboxylic acid (HMFCA) reactive intermediate. Synergistic effects between moderate strength base sites within alkali-free hydrotalcites and high gold surface concentrations can afford highly selective and entirely heterogeneous catalysts for aqueous phase aldehyde and alcohol cascade oxidations pertinent to biomass transformation.

Publication DOI: https://doi.org/10.1039/c5sc00854a
Divisions: Engineering & Applied Sciences > European Bioenergy Research Institute (EBRI)
Engineering & Applied Sciences > Chemical engineering & applied chemistry
Engineering & Applied Sciences
Related URLs:
Additional Information: This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. Funding: EPSRC (EP/G0075944); Leadership Fellowship; Studentship support; Royal Society for an Industry Fellowship; Diamond Light Source for a beam time award (SP8688).
Uncontrolled Keywords: Chemistry(all)
Published Date: 2015-08

Download

[img]

Version: Published Version

License: Creative Commons Attribution

Export / Share Citation


Statistics

Additional statistics for this record