Reports: UNI651170-UNI6: Synchrotron Photoionization Studies of Reaction Products and Intermediates of Biofuel Molecules Combustion

Giovanni Meloni, PhD, University of San Francisco

During the September 1, 2012 – August 31, 2013 period we collected data for several systems at the Advanced Light Source (ALS) of Lawrence Berkeley National Laboratory. Specifically, we used the multiplex time- and energy-resolved photoionization mass spectrometer located at the Chemical Dynamics Beamline. We also performed experiments at the Swiss Light Source (SLS) in Switzerland for the second year in a row, where we received beamtime allocation to study some biofuel molecules.

Using the photoionization mass spectrometer at the ALS in conjunction with pulsed-photolytic Cl-initiated oxidation we investigated the low temperature (550-750 K) and low pressure (8 Torr) combustion of methyl and ethyl esters, the results of which were presented at the 245thACS National Meeting, Combustion Chemistry Symposium, in New Orleans Louisiana on April 7-11, 2013. The title of the oral presentation was “Oxidation of oxygenated biofuels: Products and intermediates identification via synchrotron photoionization mass spectrometry.” We are finalizing the relative manuscript.

We also investigated the absolute photoionization cross sections of some furanic and lactonic biofuels, which was published this year in the International Journal of Mass Spectrometry.

Tert-amyl methyl ether (TAME) and ethyl tert-butyl ether (ETBE) oxidations data are being analyzed, and we expect to finalize their manuscripts by the end of the year.

During the second year of this PRF grant, four undergraduates and four graduate MS students were supported with summer stipends. The undergraduates worked for a 10-week period. Two of them are going to present their work in the poster session of the 2013 Western Regional Meeting being held in Santa Clara, California in October 2013. In addition, one MS student and one undergraduate had the financial support to travel to the SLS in Villigen, Switzerland to carry out experiments, which are a new scientific direction we are interested in pursuing. We studied the photoionization behavior of furfural via imaging photoelectron photoion coincidence (iPEPICO) spectrometry.

I have been highly motivated in engaging undergraduate students in my research program. Even though they perform experiments and are actively involved in the data analysis, undergraduates do not possess the in-depth knowledge required to put results in context. Therefore, besides providing my attention and knowledge, this year I decided to pair each undergraduate with a graduate student. In this way they benefited from a continuous guidance having the possibility to ask questions and to learn the data analysis techniques used in our group.  

Two MS graduate students were accepted into PhD programs in Chemistry, at Brown University and Johns Hopkins University. Two undergraduates, who spent last summer in my lab, were accepted in a MS Engineering program at the University of Southern California and a PhD program in Physics at Ohio State University.

This ACS-PRF grant gave me the opportunity to branch out in a different experimental technique (iPEPICO) with the work performed at the SLS, allowing me to further develop my scientific research. In addition, this international experience for my students was priceless and possible only thanks to this grant.