posted on 2023-12-26, 01:43authored byTobias Esser, André Wassenberg, Jan-Christian Raabe, Dorothea Voß, Jakob Albert
The main objective of this study was to gain a deeper
understanding
of oxidative valorization of humins using polyoxometalate (POM) catalysts. Based on experiments using individual monofuran
derivatives as a substrate, evident reaction pathways for the conversion
to maleic acid were postulated. By analogous routes, difuran derivatives
or branched furan rings could also be converted to maleic acid and
formic acid, respectively. Hereby, the monovanadium-substituted catalyst
was found to be superior compared to other structures in terms of
activity and selectivity due to its unique electrochemical properties.
In detail, H4[PVMo11O40] showed the
lowest peak potential in Square-Wave-Voltammetry measurements, achieving
the highest activity and carboxylic acid selectivity. Hereby, a deeper
understanding of the selective oxidation of humin model substrates
like furan derivatives of varying complexity could be achieved. Therefore,
helpful conclusions can be drawn for the transformation of humins
representing a decisive step toward efficient processes for their
valorization.