(590b) Selective Oxidation of Carbon Monoxide to Carbon Dioxide over Cobalt-Based Supported Catalysts for Hydrogen Clean-up in P.E.M. Fuel Cells | AIChE

(590b) Selective Oxidation of Carbon Monoxide to Carbon Dioxide over Cobalt-Based Supported Catalysts for Hydrogen Clean-up in P.E.M. Fuel Cells

Authors 

Yung, M. M. - Presenter, Ohio State University


Fuel processing for fuel cell applications is an area that is receiving much attention due to the promise of higher efficiencies and lower emissions that fuel cells offer. For PEM fuel cells, purity of the hydrogen feed stream needs is an area of concern, since even very low concentration of CO can poison the catalyst on the anode side. Hydrogen streams, however, can contain substantial amounts of CO impurities after the water-gas shift reaction. In order to avoid poisoning of the fuel cell anode, CO concentrations should be reduced to < 10 ppm. Our studies focus on the development of a catalyst that is active at low temperatures (25-150°C) and can use oxygen to preferentially oxidize CO to CO2 in hydrogen-rich streams, while avoiding the side reaction between hydrogen and oxygen. Cobalt-based catalysts on metal oxide supports have been shown to be highly promising, achieving high selectivity and activity. Steady-state kinetic experiments were conducted to determine catalyst activity. Synthesis parameters including composition, synthesis technique, metal doping, and calcination temperature were investigated. Structural and chemical characterization was performed using BET surface area measurements, in-situ X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis combined with differential scanning calorimetry. Mechanistic studies by temperature programmed desorption (TPD), laser Raman spectroscopy (LRS), and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) were also performed. Additionally, deactivation and regeneration steps were examined.