 Research
Education
Publications
Eric Stuve's ChemE
Department Listing
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Research Overview
The UW Electrochemical Surface Science
(UWESS) group examines surface science
phenomena related to electrochemical
situations, with an emphasis on fuel cells
and related technologies. Current projects
include electrochemical reforming of
biomass to hydrogen, density functional
theory of water adsorption and diffusion,
the role of electric field in water
ionization and surface reactions, and
oxidation reactions in hydrocarbon-fueled
solid oxide fuel cells.
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Eric M.
Stuve
Professor of Chemical Engineering
University of Washington
206-543-0156
stuve@uw.edu |
Electrocatalytic
Reforming of Biomass for Hydrogen
Production
Concerns about a finite energy supply,
geopolitical issues, and environmental
impact of fossil fuels motivate research in
biofuel production. Biomass is an abundant
resource, but not easily converted to a
usable transportation fuel.
Hydrogen production is one of the key
processes in a refinery, important for
liquid fuel production and in fuel cells.
Electrocatalytic reforming of biomass is an
attractive option for hydrogen production,
as it naturally separates hydrogen and
offers greater control of the reaction. We
are examining this process by reforming of
ethylene glycol, the simplest sugar:
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Anode: |
C2H6O2
+ 2 H2O —>
2 CO2 + 10 H+
+ 10 e– |
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Cathode: |
2 H+
+ 2 e– —> H2
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Successful electrocatalytic reforming
requires effective electrooxidation, which
typically is hampered by formation of
poisons at the anode, and the motivation of
this work is to find conditions favor
reaction.
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Adsorption and
Diffusion of Water
A general phenomenon in the study of surface
science involves adsorption systems with
similar substrate--adsorbate (SA) and
adsorbate--adsorbate (AA) interactions,
exemplified by water adsorption on late
transition metals. We have examined
water adsorption and diffusion on Pt(111)
terrraces and stepped and kinked Pt sites
for Pt-water adsorption energies, hydrogen
bonding among adsorbed water molecules, and
diffusion pathways of both monomeric and
polymeric water species, and activation
energies of diffusion. These studies
also show how water wets a Pt surface: water
diffuses from terrace sites, to step sites,
and to kink sites. With varying
diffusion activation energies throughout the
process.
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Field
Ionization of Water
Considered at the molecular level, water
at a metal surface exists in an extreme
environment for, in addition to the
balance of forces between chemisorption
and hydrogen bonding, there exists an
electric field on the order of several
V/Å. Fields of this magnitude
distort molecules, induce ionization, and
break bonds, and thus play a central role
in interfacial water chemistry. As
examples, self-ionization of water,
(H2O)m+n+1
—> (H2O)mH+
+ (H2O)nOH–,
the foundation of nearly all aqueous
chemistry, is itself field dependent, and
the orientation of adsorbed water in an
electrochemical environment is affected by
electric field. This work examines the ways
in which surface electric fields affect
water, its ionization, and surface reactions
from the standpoint of electrode/electrolyte
interfacial chemistry.
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Oxidation of
Hydrocarbon Fuels at Solid Oxide Anodes
Solid oxide fuel cells (SOFC) provide an
opportunity for fuel-flexible fuel cells
that operate at higher efficiencies than
other types of fuel cells. Some of the
issues faced in direct hydrocarbon oxidation
are: (1) avoiding carbon formation on the
anode and (2) understanding the role of
oxide ions in the reaction mechanism. To
address these issues we have developed
measurements that highlight the interplay of
fuel oxidation kinetics, carbon deposition
on the anode, and transport of oxide ions
through the electrolyte. Results, obtained
for a number of different fuels show some
fascinating behaviors, including induction
periods for electrocatalytic oxidation,
spontaneous and forced oscillations, and
coupled reforming with direct surface
reaction. The overall implication is
that catalyst activity is a strong function
of electrolyte structure, ionic flux, and
adsorption kinetics of the fuel. This work
was funded by the Office of Naval Research.
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Energy Facts and
Figures
This one-page article summarizes topics
covered in the Energy and Environment course
(CHEM E/ ENVIR / M E 341, Autumn 2012). It
can be used as is or printed out and pasted
onto two double-sided 3 1/2 x 5 inch cards
or four single-sided cards. This material is
for informational, instructional, or
preliminary design purposes. Because of
approximations used in presenting data, this
sheet should not be used for process or
equipment design beyond the preliminary
stage.
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Fuel
Cell Engineering
The Fuel Cell Engineering course (CHEM E
445) gives students an in-depth exposure to
science and technology of fuel cells.
By comparative study of proton exchange
membrane (PEM) and solid oxide fuel cells
(SOFC), students learn the underlying
fundamentals of these two technologies,
assessment of their performance, and how to
match fuel cells to their intended
application. More than 300 UW students
and 100 off-campus students have taken this
course since its introduction in 1996.
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Logarithmic Error
Bars
The "log error bars" article has proven
popular over time and is included here to
help those who would like to calculate and
display error bars properly on logarithmic
plots. It has recently been updated to
improve clarity and provide reference
information.
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Fuel Cell Symbol
A fuel cell combines chemical and electrical
engineering in one unit. It is
inherently a complex device requiring
special considerations both chemically and
electrically. The symbol at right
provides a convenient means for representing
a fuel cell in combined chemical process and
electrical circuit diagrams and for either
diagram separately.
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