Emerging Frontiers in Chemistry and Chemical Engineering

Emerging Frontiers in Chemistry and Chemical Engineering

mask John M. Vohs

John M. Vohs

Carl V. S. Patterson Professor of Chemical Engineering

Chair of the Department of Chemical and Biomolecular Engineering

University of Pennsylvania, USA


Advances in Ceramic Membrane Reactors: from Fuel Cells to Syngas Production

Reactors that use ceramic membranes that are either ionic or mixed ionic and electronic conductors are receiving increased attention due to the fact that such systems have the potential to have higher overall efficiencies and higher reaction selectivities than more conventional designs.

Solid oxide fuel cells (SOFC) which make use of a ceramic membrane that is an oxygen ion conductor are a good example of this technology. These systems exhibit high efficiency for electrical power generation and, at least in theory, are much more fuel flexible than other fuel cell designs. In this talk I will give an overview of our research program on the development of this type of reactor with an emphasis on the novel methods we have developed to control the structure and composition of the surfaces of the membranes. Much of the talk will focus on the use of infiltration techniques to synthesize high performance SOFC anodes that are fuel flexible allowing both hydrogen and hydrocarbons to be used to power the fuel cell. Our approach involves impregnating a porous matrix composed of the yttria-stabilized zirconia electrolyte with materials that have been optimized for both their catalytic and electronic properties. The influence of the microstructure of the electrode on catalytic performance and the development of thermally stable cathodes for SOFC and the use of mixed ionic and electronic conducting membranes for steam reforming of methane to produce hydrogen will also be discussed.


Professor John M. Vohs holds a Bachelor of Science Degree in Chemical Engineering from the University of Illinois, and a Ph.D. Degree, also in Chemical Engineering, from the University of Delaware.

He joined the faculty at the University of Pennsylvania in 1989 where he is currently the Carl V. S. Patterson Professor of Chemical Engineering and Chair of the Department of Chemical and Biomolecular Engineering. His research interests are in the areas of surface science, catalysis, membrane reactors, and solid-state electrochemistry, and his group specializes in elucidating structure-activity relationships for a variety of catalytic materials, including metals and metal oxides, and the development of anodes and cathodes for solid oxide fuel cells and electrolyzers. Current research projects in his group focus on supported metals catalysis, understanding the catalytic pathways for the reforming of bio-derived molecules, such as ethanol and glucose, to produce hydrogen and fuels, and using electrochemical techniques to characterize fuel cell and other catalysts. Prof. Vohs has authored 300 publications that have appeared in scientific journals and holds seven U.S. Patents.

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