Tag Archives: elad gross

Chemistry on the Edge: Study Pinpoints Most Active Areas of Reactions on Nanoscale Particles

Experiments at Berkeley Lab confirm that structural defects at the periphery are key in catalyst function

Defects and jagged surfaces at the edges of nanosized platinum and gold particles are key hot spots for chemical reactivity, a team of researchers working at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) and the Hebrew University of Jerusalem in Israel confirmed with a unique infrared probe. (more…)

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More Bang for the Biofuel Buck

Berkeley Lab Researchers Combine Old Fermentation Process For Making Explosives with New Chemical Catalysis to Boost Biofuel Production

A fermentation technique once used to make cordite, the explosive propellant that replaced gunpowder in bullets and artillery shells, may find an important new use in the production of advanced biofuels. With the addition of a metal catalyst, researchers at the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) have shown that the production of acetone, butanol and ethanol from lignocellulosic biomass could be selectively upgraded to the high volume production of gasoline, diesel or jet fuel.

Using the bacterium Clostridium acetobutylicum, the Berkeley Lab researchers fermented the sugars found in biomass into the solvent acetone and the alcohols butanol and ethanol, collectively known as “ABE” products. They then catalyzed these low carbon number products with the transition metal palladium into higher-molecular-mass hydrocarbons that are possible precursors to the three major transportation fuel molecules. The specific type of fuel molecule produced – whether a precursor to gasoline, diesel or jet – was determined by the amount of time the ABE products resided with the palladium catalyst. (more…)

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The Best of Both Catalytic Worlds

Berkeley Lab Researchers Develop New Technique for Heterogenizing Homogenous Nano Catalysts

Catalysts are substances that speed up the rates of chemical reactions without themselves being chemically changed. Industrial catalysts come in two main types – heterogeneous, in which the catalyst is in a different phase from the reactants; and homogeneous, in which catalyst and the reactants are in the same phase. Heterogeneous catalysts are valued for their sustainability because they can be recycled. Homogeneous catalysts are valued for their product selectivity as their properties can be easily tuned through relatively simple chemistry.

Researchers with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) have combined the best properties of both types of industrial catalysts by encapsulating nanoclusters of a metallic heterogeneous catalyst within the branched arms of the molecules known as dendrimers. (more…)

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