UT Chem/Biochem Dept

The 2007-2008 Beckman Scholars: J. Sawyer Croley, MD

Faculty Mentor: Professor Keith J. Stevenson Length of term: Summer 07, Fall 07, Spring 08, Summer 08 Honors & Awards:University Honors (Spring 06, Fall 06, Spring 07, Fall 07, Spring 08, Fall 08); University of Texas College Scholar (2008), Phi Kappa Phi Honor Society (2008) Publications: Croley, J.; Gasco, J. Chapter 1: Historical Pearls in Neurosurgery. In The Essential Neurosurgery Companion. Thieme Medical Publishing. June 2012. Feng, Z. V.; Lyon, J. L.; Croley, J. S.; Crooks, R. M.; Vanden Bout, D. A.; Stevenson, K.; Synthesis and catalytic evaluation of dendrimer encapsulated Cu nanoparticles, J. Chem. Ed, in press; Croley, J. S.; Gonzalez, L.; Amsavelu, A.; Ho, S.; Gabay, M.; Nguyen, T.; Vijayaraghavan, G.; Feng, Z. V.; Crooks, R. M.; Vanden Bout, D. A.; Stevenson, K.; Assessment of G4-NH2 dendrimer encapsulated mono- and bimetallic nanoparticles for the reduction of nitrophenol, J. Chem. Mater., to be submitted. Where is he now?Graduated with Bachelor of Science in Biology, May 2009. He completed his medical degree at UTMB Galvesteon and is now a Resident in the Dept of Orthopedic Surgery and Rehabilitation at UTMB, Galveston. How can I contact him? sawyer.croley at gmail.com

Beckman research project in the Stevenson Group:

Download a copy of Sawyer's Research report, entitledElectroreduction of p-Nitrophenol at supported mono- and bimetallic dendrimer encapsulated catalysts

Nanoparticles are of particular interest in the field of catalysis because of their unique properties when compared to bulk materials. This proposal will use an electrochemical scheme for synthesizing nanoparticles attached to carbon nanotube supports. This method is advantageous because it yields tunable, monodisperse particles with only a fraction of their catalytic surface covered when compared to other template-based or encapsulation schemes. The deposited nanoparticles will be characterized by a combination of transmission electron microscopy, energy dispersive spectroscopy, and atomic absorbance spectroscopy.

Catalytic activity will be assessed based on the rate of hydrogenation for several model reactions. These model reactions include the hydrogenation of allyl alcohol to propanol and the reduction of nitrobenzene to aniline. The reaction products will be analyzed using gas chromatography. Specifically, the project will focus on optimizing the rate of catalysis using a combination of Au, Pd, Pt, and Cu bimetallic nanoparticles. Bimetallic nanoparticles are proposed for study because they tend to exhibit synergistic catalytic properties that are greater than monometallic analogues.

There are several different supports that can be used for the electrodeposition scheme, but this study will focus on carbon nanotubes because of their large surface area and chemical versatility. Carbon nanotubes may also play a synergistic role to enhance the catalytic activity of supported nanoparticles. In particular, nitrogen-doped carbon nanotubes has shown pockets of high electron density that act as reduction sites.¹ One part of this proposed project will focus on the effects of nitrogen-doped versus undoped nanotubes as a means of optimizing catalytic activity by modifying the catalyst support.