5-hydroxymethylfurfural and titanium-dioxide
5-hydroxymethylfurfural has been researched along with titanium-dioxide* in 4 studies
Other Studies
4 other study(ies) available for 5-hydroxymethylfurfural and titanium-dioxide
Article | Year |
---|---|
Hybrid Organic-Inorganic Anatase as a Bifunctional Catalyst for Enhanced Production of 5-Hydroxymethylfurfural from Glucose in Water.
Hybrid organic-inorganic anatase (hybrid-TiO Topics: Catalysis; Citric Acid; Furaldehyde; Glucose; Lewis Acids; Nanoparticles; Recycling; Titanium; Water | 2018 |
Selective aerobic oxidation of 5-HMF into 2,5-furandicarboxylic acid with Pt catalysts supported on TiO2 - and ZrO2 -based supports.
Pt catalysts prepared over different metallic oxide supports were investigated in the oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) in alkaline aqueous solutions with air, to examine the combined effect of the support and base addition. The base (nature and amount) played a significant role in the degradation or oxidation of HMF. Increasing amounts of the weak NaHCO3 base improved significantly the overall catalytic activity of Pt/TiO2 and Pt/ZrO2 by accelerating the oxidation steps, especially for the aldehyde group. This was highlighted by a proposed kinetic model that gave very good concentration-time fittings. Moreover, the promotion of the catalyst with bismuth yielded a PtBi/TiO2 catalytic system with improved activity and stability. Y2 O3 and La2 O3 ZrO2 -supported catalysts exhibited lower activity than Pt/ZrO2 , which suggests no cooperative effect of the weakly basic properties introduced and the homogeneous base. Quantitative oxidation of HMF (0.1 M) and high yields of FDCA (>99 %) were obtained in less than 5 h by using an HMF/Pt molar ratio of 100 and Na2 CO3 as a weak base over PtBi/TiO2 (Bi/Pt=0.22). Topics: Catalysis; Dicarboxylic Acids; Furaldehyde; Furans; Hydrogen-Ion Concentration; Kinetics; Models, Chemical; Oxidation-Reduction; Oxygen; Platinum; Sodium Bicarbonate; Temperature; Titanium; Zirconium | 2015 |
Direct Production of 5-Hydroxymethylfurfural via Catalytic Conversion of Simple and Complex Sugars over Phosphated TiO2.
A water-THF biphasic system containing N-methyl-2-pyrrolidone (NMP) was found to enable the efficient synthesis of 5-hydroxymethylfurfural (HMF) from a variety of sugars (simple to complex) using phosphated TiO2 as a catalyst. Fructose and glucose were selectively converted to HMF resulting in 98 % and 90 % yield, respectively, at 175 °C. Cellobiose and sucrose also gave rise to high HMF yields of 94 % and 98 %, respectively, at 180 °C. Other sugar variants such as starch (potato and rice) and cellulose were also investigated. The yields of HMF from starch (80-85 %) were high, whereas cellulose resulted in a modest yield of 33 %. Direct transformation of cellulose to HMF in significant yield (86 %) was assisted by mechanocatalytic depolymerization-ball milling of acid-impregnated cellulose. This effectively reduced cellulose crystallinity and particle size, forming soluble cello-oligomers; this is responsible for the enhanced substrate-catalytic sites contact and subsequent rate of HMF formation. During catalyst recyclability, P-TiO2 was observed to be reusable for four cycles without any loss in activity. We also investigated the conversion of the cello-oligomers to HMF in a continuous flow reactor. Good HMF yield (53 %) was achieved using a water-methyl isobutyl ketone+NMP biphasic system. Topics: Carbohydrates; Catalysis; Furaldehyde; Microscopy, Electron, Transmission; Phosphates; Spectroscopy, Fourier Transform Infrared; Titanium | 2015 |
Glucose reactions with acid and base catalysts in hot compressed water at 473 K.
The effects of the homogeneous catalysts (H(2)SO(4) and NaOH) and heterogeneous catalysts (TiO(2) and ZrO(2)) on glucose reactions were examined in hot compressed water (473 K) by a batch-type reactor. From the homogeneous catalyst studies, we confirmed that the acid catalyst promoted dehydration, while isomerization of glucose to fructose was catalyzed by alkali. Anatase TiO(2) was found to act as an acid catalyst to promote formation of 5-hydroxymethylfuraldehyde (HMF). Zirconia (ZrO(2)) was a base catalyst to promote the isomerization of glucose. The effects of the additives were also confirmed through fructose reactions. Topics: Catalysis; Fructose; Furaldehyde; Glucose; Hot Temperature; Isomerism; Pressure; Sodium Hydroxide; Sulfuric Acids; Titanium; Water; Zirconium | 2005 |