(7ek) Enhanced Catalytic Capability through Controlled Reaction Environments: A Merger of Solvent Effects and Rational Catalyst Design

  Satisfying the demand for energy and chemicals via
efficient and sustainable utilization of carbon resources is the defining
challenge of the 21^st century. Catalysis has the potential to
satisfy these demands by enabling the use of non-traditional resources and
enhancing the efficiency of those currently consumed. Essential to achieving
this goal is the ability to predict and design new catalytic materials, which requires
a fundamental understanding of catalytic surfaces and the associated chemical
landscape.

My PhD research experience focused on
understanding the impact of water on carbonyl reduction over supported Ru
catalysts, which is one of the key chemistries in catalytic biomass upgrading
and thought to be strongly modified by electronic effects. Through rigorous
microkinetic modelling, a quantitative understanding was developed of the
mechanism by which ketones are reduced to alcohols on a Ru surface. The
microkinetic model then provided better understanding of the effects of water on
the rate of hydrogenation; water increases the rate of hydrogenation through a
preferential stabilization of the kinetically relevant transition state on the
Ru surface via hydrogen bonding. This was confirmed by comparison with alkanes,
which are incapable of participating in hydrogen bonding and showed no
promotional effect on the rate.

My postdoctoral research at the University of
Minnesota focused on the production of renewable chemicals (diolefins) from
lignocellulosic biomass. Diolefins are key monomers in the manufacture of
synthetic rubber for technologies such as renewable car tires. Saturated
furans, derived from sugars, are converted to diolefins through an acid
catalyzed mechanism called ‘dehydra-decyclization’ that was discovered as part
of my research. This was particularly exemplified with tetrahydrofuran, where
near quantitative yields to butadiene were achieved using an all-silica zeolite
impregnated with phosphoric acid. The production of isoprene from
3-methyltetrahydrofuran was similarly demonstrated, which was optimized through
experimental high throughput catalytic screening. The technology provides a
renewable route to diolefins which serve as vital building blocks for most
polymer products in the rubber industry.

My future research direction lies at the
intersection of catalytic descriptors, hybrid reaction environments and
data-driven discovery. Much of catalyst discovery has been guided through
heuristics and inherited knowledge, where an ad-hoc approach has been adopted for
selecting better catalysts. Computational efforts provide a guided approach to
catalyst design, with volcano plots based on the Sabatier principle as a
prominent example. A significant push is yet to be made with experiments, where
large kinetic data sets of information will be required. Beyond simply
understanding catalytic functionality in traditional reaction environments, a
need exists to understand a catalyst’s behavior at varying reaction conditions.
The nature of the solvent environment in which a catalyst is placed is one such
example, which has been shown to drastically affect the rates of reaction.
Leveraging solvent effects has found beneficial applications in acid catalyzed
dehydrations, metal catalyzed reductions, selective oxidation and multiple other
catalytic systems. A solvent based approach to tuning catalyst performance
becomes especially attractive in areas such as catalytic biomass upgrading,
where the inherently high water content of biomass can be utilized. Through a
predictive understanding of how a solvent environment can affect a catalytic
surface, reaction conditions can be better tailored to maximize desired
catalytic transformations. Teaching Interests:

Research can inspire teaching. As part of my graduate
degree program, I was involved in undergraduate course development, where I
designed experiments, equipment and course material for undergraduate teaching
labs. I designed and constructed an experiment where senior year students
operated a vapor phase packed bed reactor, studying the kinetics of isopropanol
dehydration over solid acid catalysts. I also designed an experiment to
demonstrate the concept of residence time distribution (RTD) in reactors, where
students measured and applied RTD fundamentals to a series of continuously
stirred tank reactors using step tracers.  I also served as a teaching
assistant for graduate level mathematics for chemical, biomedical and
mechanical engineering students. While I would especially enjoy teaching
reaction engineering courses, both at the graduate and undergraduate level, I
am comfortable teaching many of the core chemical engineering courses (Mass
& Energy Balances, Heat & Mass transfer and thermodynamics) as well as
upper-level courses including Process Design, Unit Operations and Product
Design.