Northwestern Events Calendar

May
17
2018

ChBE Seminar Series: Student Presentations

recurring see all events in this series

When: Thursday, May 17, 2018
9:00 AM - 10:00 AM CT

Where: Technological Institute, M345, 2145 Sheridan Road, Evanston, IL 60208 map it

Audience: Faculty/Staff - Student - Public - Post Docs/Docs - Graduate Students

Cost: Free

Contact: Elizabeth Rentfro   (847) 491-2773

Group: McCormick-Chemical and Biological Engineering (ChBE)

Category: Academic

Description:

Student Presentations
Louisa Savereide - Notestein Group
Cassandra Whitford - Snurr Group

Cassandra Whitford, Snurr Group:

Title
Investigating the Complexity of Composite Nanoparticle-MOF Catalysts

Abstract
In the commodity chemicals and energy industries, there is a focus on atom-efficient chemo- or regioselective reactions that minimize the consumption of raw materials and the formation of byproducts. Composites of metal nanoparticles encapsulated by metal-organic frameworks (NP@MOFs) have recently emerged as intriguing heterogeneous catalysts for regioselective reactions. These catalysts utilize the pore system of a MOF to direct reactants to the surface of nanoparticles. While various NP@MOF composites have been synthesized and shown to be regioselective, their characterization has been limited. By coupling in situ techniques with DFT calculations to study Pt@ZIF-8 as a prototypical NP@MOF, we were able to chemically define the nanoparticle-MOF interface, identify an electronic effect imparted on the nanoparticle by the MOF, and construct a model of the encapsulated Pt surface. Further, this work highlights the necessity of characterizing the nanoparticle surface in future NP@MOF synthetic and kinetic studies due to its direct influence on catalysis.

 

Louisa Savereide, Notestein Group:

Title
Design of Highly Dispersed Cobalt Oxide Ceria-Supported Catalysts for the Reduction of NO by CO

Abstract
Developing non-precious metal catalysts for the reduction of nitrogen oxides is an important step towards reducing toxic automotive emissions. Cobalt oxide supported on ceria (CeO2) has shown promising activity for the reduction of NO. A simple, scalable technique for producing this type of catalyst is called incipient wetness impregnation (IWI). Unfortunately, IWI as it is traditionally carried out leads to a variety of types of oxide surface species, which obscures what type of site is responsible for high catalytic activity. In this work, I test several tunable synthesis handles to understand relationships between catalyst synthesis, structure, and activity. We found that independent of synthesis method, catalyst activity scales linearly with cobalt oxidation state of a fully oxidized catalyst, particularly at sub-monolayer cobalt coverage. This suggests that highly dispersed CoO sites rather than bulk Co3O4 crystallites are important for NO reduction. By systematically modifying support morphology, metal precursor chelating ligand, and additional promoter ions, we demonstrate various techniques to increase cobalt dispersion, improve catalyst activity, and understand the interaction between cobalt oxide and the ceria support.

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