Cellulosic ethanol may become an important part of a sustainable energy economy. Such ethanol has advantages over other ethanol sources such as corn ethanol, in that cellulose is overly abundant and the production of cellulosic ethanol does not require specific crops or influence global food prices. However, widespread production of cellulosic ethanol is inhibited by the high cost of converting the cellulose into glucose.
Currently, acids and enzymes are the preferred methods for converting cellulose to glucose. Enzymes cannot be re-used and are somewhat expensive to produce. Acids are cheaper, but also cannot be re-used, and have the additional unwanted effect of degrading some of the glucose produced into waste by-products, and require costly separation or neutralization before disposal into the environment. For cellulosic ethanol to compete in the marketplace with fossil fuels, the cost of converting cellulose to glucose must be minimized. An ideal catalyst would provide fast conversion of cellulose to glucose, minimal degradation of glucose into waste products, and energy efficient, inexpensive recycling and re-use capabilities.
Nanosized particles with superparamagnetic cores and acidic functional ligands possess the desired catalyst traits. Unlike enzymes, the acidic ligands are chemically stable, and resist oxidation. Superparamagnetic nanoparticle cores have diameters that are smaller than the magnetic domains of the material, allowing them to be pulled from solution by the presence of a moderate external magnetic field, and return to a non-magnetic state when the external magnetic field is removed.
Preliminary work has been conducted on the ability of some acid functionalized magnetic nanoparticles to catalyze cellulose hydrolysis.
See more of this Group/Topical: Catalysis and Reaction Engineering Division