Development of Metal-Organic Frameworks as a Versatile Platform for Heterogeneous Catalysis
University of South Florida
Metal–organic frameworks (MOFs) represent a new class of materials, and one of their striking features lies in the tunable, designable, and functionalizable nanospace. The nanospace within MOFs allows designed incorporation of different functionalities for targeted applications, such as gas storage/separation, sensing, drug delivery; and it has also provided plenty of opportunities for heterogeneous catalysis application. We will illustrate different approaches to develop MOFs as versatile platform for heterogeneous catalysis.
Electronic structure and reactivity of atmospheric ions
Kai Lister, Jennifer E. Ruliffson, Melanie White, Rachael Mizrahi, and Joshua J. Melko
University of North Florida
In atmospheric chemistry it is vital to be able to control for energetics and environment to accurately model reaction pathways and kinetics of compounds that behave differently across the atmospheric layers. Nowhere is this more evident than in the context of nitrogen oxides and isoprene. In the troposphere nitrogen oxides may react with volatile organic compounds (of which isoprene is a major contributor) to form ozone creating significant health impacts. As these compounds rise to the stratosphere nitrogen oxides are implicated in the depletion of the ozone layer and isoprene is thought to be a possible intermediate in the formation of secondary organic aerosols. Our group proposes two methods used for controlling/determining temperature and composition of gas phase nitric oxide and isoprene.
Photoelectron spectroscopy experiments in conjunction with computational methods are used to map part of the potential energy surface of nitric oxide. Nitric oxide anions are created using electron ionization and isolated via mass spectrometry, and photoelectron spectra are captured via velocity map imaging. Theoretical spectra are produced at various ion temperatures using ezSpectrum software, which calculates the Franck-Condon factors using Gaussian09 optimizations of equilibrium geometry, harmonic frequencies, and normal mode vectors.
Through the use of a mixing tank and helium damping gas, reaction pathways of isoprene were mapped by varying source conditions to control the extent of fragmentation and clustering of reaction products. This experiment allows for future work studying the formation of secondary organic aerosols to better understand the origins of cloud formation.
Extraterrestrial Contributions to the Prebiotic Inventory of the Early Earth from Meteorites
Chris J. Bennett1,2,3, Amy LeBlue-DeBartola1, Brandon Wilson1, Claire Pirim2, Jennifer Noble2, Laurene Tetard1, Alfons Schulte1, Dan Britt1, Andrew Saydjari4, Aaron McKee3, Jay Forsythe3,5, Eric Parker3,6, Ramanarayanan Krishnamurthy7, Facundo Fernandez3, Thomas Orlando3, Nicholas Hud3
1 – University of Central Florida, FL 32816
2 - Université des Sciences et Technologies de Lille, Lille, France
3 – Georgia Institute of Technology, Atlanta, GA 30332
4 – Yale University, New Haven, CT 06520
5 – College of Charleston, Charleston SC 29424
6 – NASA Goddard Space Flight Center, Greenbelt MD 20771
7 – The Scripps Research Institute, La Jolla, CA 92037
Meteorites, in particular the 4% of carbonaceous chondrites that fall to the Earth, represent some of the most primitive and unaltered bodies in the solar system that we are able to study, and could have contributed an extraterrestrial source of organics to the prebiotic Earth. Of particular interest is the presence of amino acids and related compounds which could have yielded active length peptides within the primordial environment either directly or by production within the heated environment. The amino acids and associated species are found to be in high abundance within certain types of carbonaceous chondrites (specifically CM2 and CR2 groups), presenting an opportunity to try to answer some key questions, such as: i) Are amino acids incorporated into meteorites or formed within them? ii) To what extent are these species present as free acids vs. polymeric forms within the meteorite? iii) Are there spatial associations between acids or polymer abundances with the mineral/metal components found within meteorites? And iv) Does the temperature and history of the meteorite parent body play a role in their abundances and play a role in their production/destruction mechanisms?
Here, we present some recent work investigating the process of the polymerization process on mineral surfaces as well as looking for evidences of these processes by looking at the Murchison (CM2), Allende (CV3), Jbilet Winselwan (CM2), and Tagish Lake (C2?) meteorites. A correlated approach is outlined whereby techniques including Raman and FTIR microscopy, TEM, ToF-SIMS, and some preliminary work using ESI-MS and nanoIR are helping to shed light on some of these questions.