(575ao) High Throughput Microcalorimetry for Catalyst Discovery

Our group is addressing fundamental science and engineering pathways for thermochemical conversion of woody biomass to fuels and chemicals, an area of increasing importance to Maine's forest products industry. A major technical focus is on upgrading of biomass pyrolysis oils. Roadblocks in thermally upgrading pyrolysis oil, a complex highly-oxygenated liquid, include improving the heating value through catalytic oxygen removal, identifying favorable reaction pathways, and developing production methods for optimum upgrading. Oxygen removal is accomplished by hydrodeoxygenation (HDO) of the pyrolysis oil over an appropriate catalytic metal/support combination. Pyrolysis oils are being characterized, and catalysts are being developed to improve the chemical compositions of the biomass pyrolysis products.

One element of our catalyst design effort involves combinatorial synthesis and screening. We are generating libraries of size-selective catalyst/supports combinations using engineered mesoporous (1-10 nm diameter pores) materials using rapid ink-jet synthesis techniques. The libraries are synthesized on arrays of microcalorimeters such as the one in the scanning electron microscope image below. These microfabricated devices have very sensitive thermal response characteristics because they have a low thermal mass, and they are suspended from the substrate. The method will eventually be applied to HDO of model pyrolysis oil compounds such as furfural. However, we are first qualifying our method using the Fischer-Tropsch reaction. Arrays have been created using mesoporous silica supported cobalt and iron. The energy produced during exposure to a syngas mixture is detected by the resistance change of embedded, serpentine platinum RTDs. The screening results are then compared to temperature programmed reaction studies using bulk-prepared catalysts in a microreactor catalyst characterization system.