Fundamental research at MESA+ research institute of the Univ. of Twente in the Netherlands shows that the production of hydrogen, derived from for example biomass, can in principle be much more efficient. PhD candidate Shilpa Agarwal demonstrated that the physical form and size of the catalyst CeO2 play a significant part. For example, she showed that cube-shaped nanoparticles of the material possess the highest activity. Agarwal's PhD defence is scheduled for April 3, 2014.
Biomass is a good alternative for fossil fuels, but converting biomass into useful chemicals and fuels is difficult in practice. As first step in the process, biomass is converted into smaller molecules, for example by using the flash pyrolyse method. A suitable conversion method for the resulting bio-based molecules is “steam reforming”, whereby water (in the form of steam) and the molecules react, thus forming hydrogen, which can be used as fuel or to upgrade fuels. For this process, you need a suitable catalyst to speed up the reaction. The metal oxide CeO2 is known for being a suitable catalyst component for activating water, but until recently it was not clear in which form the reactivity of this catalyst was highest. PhD candidate Shilpa Agarwal, who conducted fundamental research on the activation of water, showed that CeO2 crystals in the form of a cube possess the highest reactivity per square metre.
In her research, she created several nanostructures of the material by adjusting the temperature, time and the acidity of a saturated solution in which the crystals form and grow. Reactivation studies consequently showed that minuscule 10 to 100 nm cubes possess the highest reactivity.
Agarwal carried out her research in the Catalytic Processes and Materialsdepartment of the Univ. of Twente Mesa+ research institute. She was supervised by dr. Barbara Mojet and prof. dr. ir. Leon Lefferts. The research is part of the UT's Green Energy Initiative and has been made possible by ADEM.
Source: Univ. of Twente