Tuning Active Sites in Catalytic Nanomaterials through Colloidal Synthesis
Christina W. Li
Associate Professor
Purdue University

Abstract
Supported metal atoms and nanoparticles are found ubiquitously as heterogeneous catalysts for a wide
variety of industrial, organic, and energy catalytic processes. The electronic and steric environment at thenanomaterial surface has a huge impact on the reactivity and selectivity of catalytic transformations
occurring at surface active sites, but these properties are difficult to independently control throughconventional materials synthetic methods. In this work, we develop molecularly-precise surfacefunctionalization strategies in order to precisely tune both the ensemble geometry and redox properties ofactive site metal atoms. These strategies include 1) the adsorption of inorganic ligands on colloidal
nanoparticle surfaces in order to synthesize monolayer and sub-monolayer core-shell catalysts, 2) controlof bimetallic surface ensemble geometry to catalyze diastereoselective organic reactions, and 3) tuning
the metal–sulfur coordination environment of single atoms supported on metal chalcogenide nanosheetsfor electrochemical catalysis. All of these strategies develop new structural frameworks for modulating
the surface active site environment in order to access more reactive and selective nanomaterial catalysts.
BioChristina Li received an A.B. in chemical and physical biology from Harvard University in 2009, workingwith Professor David Evans. She completed her Ph.D. in chemistry at Stanford University, working withProfessor Matthew Kanan on nanostructured Cu electrodes for CO2 reduction. She then did postdoctoral
work at UC Berkeley with Professor Paul Alivisatos on colloidal semiconductor nanocrystals. She began
her independent career in the chemistry department at Purdue University in 2016 where her group focuseson colloidal synthetic strategies to tune the electronic properties and ensemble geometry of nanoparticle
active sites for electrochemical, thermal, and organic catalytic reactions. She was promoted to associate
professor in 2023. She has received a National Science Foundation CAREER Award, a National Institutesof Health Maximizing Investigators’ Research Award (MIRA), and the 2024 ACS Catalysis Lectureship.

Catalytic Transfer Reactions of Non-stabilized Carbenes
Christopher Uyeda

AbstractCarbenes are versatile reactive intermediates that display orthogonal reactivity tocommon nucleophilic and electrophilic functional groups. Catalytic carbene transfer reactions
were first discovered over a century ago, and numerous examples of [n + 1]-cycloaddition
reactions have since been developed, often with control over diastereo- and enanatioselectivity.
Most of these reactions rely on the controlled decomposition of diazoalkanes as a central
strategy to access reactive carbene equivalents.
Despite the utility of diazoalkanes in organic synthesis, they are inherently limited by theneed for stabilizing substituents such as aryl or carbonyl groups. In order to develop transfer
reactions of nonstabilized carbenes, it is necessary to consider an alternative set of precursors.
Our group has shown that nickel and cobalt catalysts can promote reductive [n + 1]cycloaddition reactions using readily available and indefinitely stable 1,1-dichloroalkanes and1,1-dichloroalkenes as precusors for carbenes and vinylidenes, respectively. In this seminar, I
will describe our development of new cycloaddition methods and our current hypotheses about
the mechanisms of these reactions.
BioChris Uyeda is the Herbert C. Brown Professor of Chemistry at Purdue University. After
growing up in Vancouver, Canada, he attended Columbia University, where he earned his B.S.
in biomedical engineering in 2005. As an undergraduate student, Chris carried out research onhydrophobically directed reactions with Prof. Ronald Breslow. Chris then moved to Harvard
University to pursue graduate research under the supervision of Prof. Eric Jacobsen. He
obtained his Ph.D. in 2011, and his thesis described the development of catalytic
enantioselective Claisen rearrangements using chiral hydrogen bond donors. Chris then carriedout postdoctoral research with Prof. Jonas Peters at Caltech as an NSF CCI Fellow. His work
involved studying electrocatalysts for the production of solar fuels. In 2013, Chris started his
independent career at Purdue University. His research program currently focuses on studying
catalytic reactions at metal–metal bonds, discovering new catalytic carbene transfer reactions,and synthesizing conjugated materials containing N=N bonds.