608-53-7Relevant articles and documents
Selective Conversion of Various Monosaccharaides into Sugar Acids by Additive-Free Dehydrogenation in Water
Mollar-Cuni, Andres,Byrne, Joseph P.,Borja, Pilar,Vicent, Cristian,Albrecht, Martin,Mata, Jose A.
, p. 3746 - 3752 (2020/06/01)
Abundant sugars of five and six carbon atoms are promising candidates for the production of valuable platform chemicals. Here, we describe the catalytic dehydrogenation of several pentoses and hexoses into their corresponding sugar acids with the concomitant formation of molecular hydrogen. This biomass transformation is promoted by highly active and selective catalysts based on iridium(III) complexes containing a triazolylidene (trz) as ligand. Monosaccharides are converted into sugar acids in an easy and sustainable manner using only catalyst and water, and in contrast to previously reported procedures, in the absence of any additive. The reaction is therefore very clean, and highly selective, which avoids the tedious purification and product separation. Mechanistic investigations using 1H NMR and UV-vis spectroscopies and ESI mass spectrometry (ESI-MS) indicate the formation of an unprecedented diiridium-hydride as dormant species that correspond to the catalyst resting state.
Aerobic oxidation of xylose to xylaric acid in water over pt catalysts
Sadula, Sunitha,Saha, Basudeb
, p. 2124 - 2129 (2018/10/20)
Energy-efficient catalytic conversion of biomass intermediates to functional chemicals can make bio-products viable. Herein, we report an efficient and low temperature aerobic oxidation of xylose to xylaric acid, a promising bio-based chemical for the production of glutaric acid, over commercial catalysts in water. Among several heterogeneous catalysts investigated, Pt/ C exhibits the best activity. Systematic variation of reaction parameters in the pH range of 2.5 to 10 suggests that the reaction is fast at higher temperatures but high C C scission of intermediate C5-oxidized products to low carbon carboxylic acids undermines xylaric acid selectivity. The C C cleavage is also high in basic solution. The oxidation at neutral pH and 60 8C achieves the highest xylaric acid yield (64 %). O2 pressure and Pt amount have significant influence on the reactivity. Decar-boxylation of short chain carboxylic acids results in formation of CO2, causing some carbon loss; however, such decarboxyla-tion is slow in the presence of xylose. The catalyst retained comparable activity, in terms of product selectivity, after five cycles with no sign of Pt leaching.
Highly selective photocatalytic oxidation of biomass-derived chemicals to carboxyl compounds over Au/TiO2
Zhou, Baowen,Song, Jinliang,Zhang, Zhanrong,Jiang, Zhiwei,Zhang, Pei,Han, Buxing
, p. 1075 - 1081 (2017/03/17)
Highly selective transformation of biomass-derived chemicals into value-added chemicals is of great importance. In this work, selective photooxidation of various biomass-derived chemicals, including ethanol, glucose, xylose, 2-furaldehyde, 5-hydroxymethyl-2-furfural, and furfuralcohol to the corresponding carboxyl compounds was studied using atmospheric air as the oxidant at ambient temperature. It was found that the reactions could be carried out efficiently over Au nanoparticles (AuNPs) supported on TiO2 (AuNPs/TiO2) under both ultraviolet (UV) and visible light in Na2CO3 aqueous solution. Under the optimized conditions, the selectivities for desired products were higher than 95% for all the reactions. Detailed studies indicated that the surface plasmon resonance of AuNPs and the band-gap photoexcitation of TiO2 were responsible for visible-light-responding and UV-light-responding activities, respectively. Na2CO3 acted as the promoter for the visible-light-induced oxidation and the inhibitor of reactive oxygen species with strong oxidation power under UV light.
