With petrol prices on the rise, biofuels are big news these days. For applications in the transportation sector, perhaps the best known liquid biofuel is biomass-derived ethanol. But ethanol has its limitations: it is highly volatile, absorbs water and has a low energy density. A team from the University of Wisconsin-Madison has developed a two-step catalytic process that can convert fructose into a potentially better liquid biofuel, 2,5-dimethylfuran (DMF). This has 40%-higher energy density and a higher boiling point than ethanol, and is not water soluble. Fructose can be made directly from biomass or from glucose and although there's some work needed before DMF production can be made commercially viable, this new catalytic process looks promising. Diminishing fossil fuel reserves and growing concerns about global warming indicate that sustainable sources of energy are needed in the near future. For fuels to be useful in the transportation sector, they must have specific physical properties that allow for efficient distribution, storage and combustion; these properties are currently fulfilled by non-renewable petroleum-derived liquid fuels. Ethanol, the only renewable liquid fuel currently produced in large quantities, suffers from several limitations, including low energy density, high volatility, and contamination by the absorption of water from the atmosphere. Here we present a catalytic strategy for the production of 2,5-dimethylfuran from fructose (a carbohydrate obtained directly from biomass or by the isomerization of glucose) for use as a liquid transportation fuel. Compared to ethanol, 2,5-dimethylfuran has a higher energy density (by 40 per cent), a higher boiling point (by 20 K), and is not soluble in water. This catalytic strategy creates a route for transforming abundant renewable biomass resources1,2 into a liquid fuel suitable for the transportation sector, and may diminish our reliance on petroleum.

Production of dimethylfuran for liquid fuels from biomass-derived carbohydrates

Catalysis by alloys and bimetallic clusters

https://pure.tue.nl/ws/files/2325948/620870.pdf

Determination of metal particle size of highly dispersed Rh, Ir, and Pt catalysts by hydrogen chemisorption and EXAFS

Model studies on bimetallic Cu/Ru catalysts: II. Adsorption of hydrogen

Titania-supported copper-manganese mixed oxides were investigated in view of the selective oxidation of ammonia to dinitrogen and characterized by X-ray diffraction, photoelectron spectroscopy and temperature programmed reduction. The mixed oxides proved to be more active than the corresponding individual oxides. The TPR-results show that the reduction occurs at lower temperatures than that of the unsupported oxides. It is concluded that titania facilitates the change of oxidation states. Most active and selective for N2-formation is a catalyst with a molar ratio of Cu: Mn = 20:80. It contains a crystalline Cu1+xMn2−xO4 spinel phase (determined by XRD) and an additional X-ray amorphous Mn2+ -containing species (determined by XPS), possibly Mn3O4 or MnO. Copper is present in the mono- and divalent oxidation state (shown by XPS). All catalysts hardly loose activity with time on stream, above all the copper-rich catalysts are very stable.

A.E. Barnett

Papers

Nature of ruthenium-copper catalysts