0000000000348760
AUTHOR
Salvador Ordóñez
Selective photocatalytic oxidation of 5-hydroxymethylfurfural to 2,5-furandicarboxaldehyde by polymeric carbon nitride-hydrogen peroxide adduct
Abstract Polymeric carbon nitride-hydrogen peroxide adduct (PCN-H2O2) has been prepared, thoroughly characterised and its application for selective photocatalytic conversion of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxaldehyde (FDC) in aqueous suspension has been studied. The PCN-H2O2 adduct is stable in aqueous suspension under UV and solar irradiation up to 100 °C. It is also stable up to 200 °C if heated in air, while at temperatures close to 300 °C its decomposition takes place. Based on the obtained characterisation data it has been proposed that H2O2 attaches to the non-polymerised carbon nitride species and to the heptazine nitrogen atoms, thus producing strong hydrogen bond…
Effect of Substituents on Partial Photocatalytic Oxidation of Aromatic Alcohols Assisted by Polymeric C3N4
In the present work we scrutinize the effect of substituents in the phenyl ring of the benzyl alcohol on its photo-oxidation to the corresponding benzaldehyde driven by polymeric carbon nitride photocatalyst in aqueous medium. It has been established that electron donating (ED) substituents in para- and ortho-position with respect to the CH2OH-group promote the reactivity of the substrate without compromising the selectivity towards benzaldehyde formation, maintaining it in the range of 84–98 %, if compared to the unsubstituted molecule. The same observation is true for meta-substituted benzyl alcohol with an electron withdrawing (EW) group. On the other hand, the presence of ED-group in me…
Selective photocatalytic oxidation of 5-hydroxymethyl-2-furfural in aqueous suspension of polymeric carbon nitride and its adduct with H2O2 in a solar pilot plant
Abstract This work reports a study on the reactivity of polymeric carbon nitride (PCN) and PCN-H2O2 adduct samples for sunlight photocatalytic selective oxidation reactions. The characterization of these materials was reported in a previous paper where the reactivity towards the partial oxidation of 5-hydroxymethylfurfural (HMF) was studied by using two different laboratory scale photoreactors; one irradiated by UV lamps and the other one by natural sunlight. In the present study it has been confirmed the effectiveness of these C3N4 based materials for the selective partial oxidation of HMF to FDC (2,5-furandicarboxaldehyde) in aqueous medium in a pilot plant photoreactor irradiated by natu…
Selective photocatalytic oxidation of 5-hydroxymethyl-2-furfural to 2,5-furandicarboxyaldehyde in aqueous suspension of g-C3N4
Graphitic carbon nitride assisted partial photocatalytic oxidation of 5-hydroxymethyl-2-furfural (HMF) in aqueous medium was investigated. Different carbon nitride precursors were considered, being melamine the one yielding the most efficient photocatalyst. The obtained 30% selectivity of HMF oxidation to 2,5-furandicarboxaldehyde (FDC) is higher than those reported up to now. A further thermal exfoliation of the g-C3N4 samples showed under artificial light irradiation both an enhanced photocatalytic activity in conversion of HMF, and selectivity (ca. 42–45%) to FDC. The performance of the catalysts increased when the experiments were carried out under real outdoor illumination, reaching 50…