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AGEP-T FRAME Fellow: Robert Palomino Ph.D.



Robert Palomino

Ph.D: Chemistry, Stony Brook University

AGEP-T FRAME Placement: Department of Chemistry, Brookhaven National Laboratory         

AGEP-T FRAME Research Mentor: Dr. Jose Rodriguez

Email: Robert.Palomino@stonybrook.edu


Born and raised on Long Island, NY in the town of Rockville Centre, Robert Palomino always had an interest in the STEM field. Robert attended St. John's University in 2003, where he majored in Chemistry. During his undergraduate years, he was accepted into the Initiative for Minority Student Development (IMSD) research program where he conducted research on phosphine-based ligands in biphasic heterogeneous catalysts for use in organic-ionic solutions. Additionally, he was involved in a summer REU at Georgetown University where he researched Cu-base organometallic catalysts for hydrocarbon functionalization. His efforts on this project lead to a publication in 2008. He graduated from St. John's University with his B.S. in 2007.

Robert attended Stony Brook University, where he joined the Dr. W. Burghardt Turner Fellowship in 2007. Shortly after, he was awarded an NSF GRFP Fellowship to conduct research at Stony Brook University with Dr. Michael White. His Ph. D. project in Dr. White's group focused on the in situ characterization of promoted Rh nanocatalysts towards the conversion of synthesis gas (CO + H2) to ethanol. His research results were published in a high ranking peer-reviewed journal. Robert earned his Ph. D. in July 2015 and promptly began an AGEP-T FRAME postdoctoral research project at Brookhaven National Laboratory in August 2015, working with Dr. Jose Rodriguez on synchrotron-based studies of CO2 hydrogenation catalysts towards alcohol synthesis.

Seminar Topic: Ambient Pressure Studies of Model Catalysts for CO Oxidation, Water-gas Shift, and Methanol Production

For decades, CO oxidation, the water-gas shift reaction, and methanol production has been heavily researched due to the potential for CO mitigation and clean hydrogen production. Nanoparticulate Au or Cu supported over metal oxides such as TiO2, CeO2, Al2O3, and ZnO have shown to exhibit enhanced catalytic efficiency for these reactions. Although these catalysts have been extensively studied, improvements to increase their efficiency are still necessary. This is partly due to the lack of a complete understanding of what causes the enhancement of catalytic efficiency. Powdered or 'real' catalysts, consisting of nanoconfined metal particles supported over metal oxide powders, show the highest reactivity. However, they are complex in nature containing multiple components such as multiple ranges of particle sizes, multifaceted crystallites, varying particle shapes, and the interfaces between them, all of which may perform different roles. With such complex catalytic systems, it is of no surprise that the precise cause for catalytic enhancement has not been conclusively elucidated.

Model catalysts, which are simplified versions of the 'real' catalysts, can study specific components of the 'real' catalyst in order to determine their role or affect that components have on the reaction efficiency. This could mean studying a particular crystal face, precisely controlling the particle size of the active metal, or studying the effect of the interface between the metal and metal oxide using an inverse catalyst (the metal oxide is supported on the active metal single crystal). While this type of study focuses on isolated components in a catalytic system, the results obtained are challenging to compare to those from its 'real' counterpart. This is because the majority of the techniques used in these studies need to be conducted under ultra-high vacuum (UHV) conditions. The catalyst often behaves differently when operating under UHV compared to under high pressures, so the results obtained from each can invalidate one another. The logical solution is to perform these same studies under higher pressures, which wasn't possible until recently.

Our work focuses on studying conventional and inverse Au- and Cu-based model catalysts for use in ambient pressure studies during CO oxidation, water-gas shift, and methanol production. By utilizing Ambient Pressure X-ray Photoelectron Spectroscopy (AP-XPS) and Ambient Pressure X-ray Absorption Spectroscopy (AS-XAS), the local electronic (and to a degree, atomic) structure of these model catalysts, along with the bound reactants and reaction intermediates, can be studied during these important reactions at near ambient pressures (up to several Torr). These techniques bridge the pressure gap between model and 'real' catalysts and allow us to study the simplified components of these active catalysts under controlled conditions. This enables us to elucidate the role of these specific components during the reaction at higher pressures.[1, 2]

1. Rodriguez, J.A., et al., The Activation of Gold and the Water-Gas Shift Reaction: Insights from Studies with Model Catalysts. Accounts of Chemical Research, 2014. 47(3): p. 773-782.

2. Mudiyanselage, K., et al., Importance of the Metal–Oxide Interface in Catalysis: In Situ Studies of the Water–Gas Shift Reaction by Ambient-Pressure X-ray Photoelectron Spectroscopy. Angewandte Chemie International Edition, 2013. 52(19): p. 5101-5105.