Maria A Gomez

Professor

Department of Chemistry

Mount Holyoke College

 
 
 

Overview of our work:

Geological limitations in the supply of petroleum products as well as stricter emissions regulations have sparked interest in developing alternative sources of energy. Fuel cells, which are estimated to be twice as efficient as the best combustion engine, avoid the entire combustion process by directly converting chemical energy into electrical energy. As a result, they emit significantly fewer pollutants and reduce dependence on petroleum products.

Proton conduction speeds and mechanisms vary among different materials and temperature regimes. Polymer electrolyte, solid acid salt, and perovskite fuel cells show promise at temperatures ranges below 100°C, 160-400°C, and 400-600°C, respectively. From the lowest to highest temperature conductors, the network for proton conduction changes from a network of liquid water with hydrogen bonds to one of more rigid oxygen binding sites. The proton conduction mechanism changes through these materials not simply due to changing conduction network but also due to the changing character of the proton. While not as light as the electron, protons still exhibit significant quantum mechanical character at low temperatures.

Understanding how the proton conduction mechanism changes with material and quantum character should help design better proton conducting materials. Since the proton quantum character increases as the temperature decreases, our research group simulates high temperature conductors where classical simulation treatment is reasonable and also low temperature conductors where quantum treatment is crucial. 

Fundamental areas considered in our work:

Research in this area covers a wide range of ideas from:  thermodynamics, statistical mechanics, classical mechanics, and quantum mechanics.  Further, fuel cell materials range significantly in structure allowing us to consider fundamental ideas in a variety of media and necessitates constructing models for: solid phases, solid/solid interfaces, ions moving through solids and interfaces, liquid/polymer interfaces, solutes in liquids, and solid/gas interfaces.  Our research also entails using and developing mathematical ideas within physical contexts. 

SELECTED PUBLICATIONS

(*undergraduate co-authors)

M. A. Gomez and F. Liu*, “Protons in Al doped BaZrO3 escape dopant traps to access long range proton conduction highways,”  Solid State Ionics. 252, 40 (2013).

M. A. Gomez, D. Shepardson, L. T. Nguyen*, T. Kehinde*, “Periodic long range proton conduction pathways in pseudo-cubic and orthorhombic perovskites,” Solid State Ionics. 213, 8 (2012).

M. A. Gomez, M. Chunduru*,L. Chigweshe*, K. M. Fletcher*, “The effect of Al an Y dopant on the proton conduction pathways of SrZrO3, an orthorhombic perovskite,” J. Chem. Phys. 133, 064701 (2010).

M. A. Gomez, M. Chunduru*,L. Chigweshe*, L. S. Foster*, S. J. Fensin*, K. M. Fletcher*, and L. F. Fernandez*, “The effect of yttrium dopant on the proton conduction pathways of BaZrO3, a cubic perovskite,” J. Chem. Phys. 132, 214709 (2010).

F. G. Haibach, M. A. Gomez, E. Fitzgerald, K. E. Paczkowski*, “NIR imaging of paintings:  Looking for deeper meaning,” Chemical Educator, 12, 349 (2007).

M. A. Gomez, Saryu Jindal*, Katharyn M. Fletcher*, Leigh S. Foster*, Nanna Dufie A Addo*, Debbie Valentin*, Cristina Ghenoiu*, and Abigail Hamilton*, “A comparison of proton conduction in KTaO3 and SrZrO3,” J. Chem. Phys. 126, 194701 (2007).

M. A. Gomez, L. R. Pratt, J. D. Kress, and D. Asthagiri, “Water adsorption and dissociation on BeO (001) and (100) surfaces,” Surface Science, 601, 1608 (2007).

M. A. Gomez, and P. Peart*, “Including quantum subsystem character within classical equilibrium simulations,” J. Chem. Phys. 125, 034105 (2006).

M. A. Gomez, M. A. Griffin*, S. Jindal*, K. D. Rule*, and V. Cooper*, “The effect of octahedral tilting on proton binding sites and transition states in pseudo-cubic perovskite oxides,” J. Chem. Phys 123, 094703 (2005).

P. Grabowski*, D. Riccardi*, M. A. Gomez, D. Asthagiri, and L. R. Pratt, “Quasi-chemical theory and the standard free energy of H+ (aq),” J. Phys. Chem. A. 106, 9145 (2002).

L. R. Pratt, R. A. LaViolette, M. A. Gomez, and M. E. Gentile*, “Quasi-chemical Theory for the Statistical Thermodynamics of the Hard Sphere Fluid.” J. Phys. Chem. B. 105, 11662 (2001).


CURRENT RESEARCH FUNDING

National Science Foundation – MRI (2013–2016)
George Shields, Maria A. Gomez, Carol Parish, Marc Zimmer, Maria Nagan, Tricia Sheperd, Maurio Cafiero, Kelling Donald, Becky Eggimann, Cliff Padgett, Eric Patterson, Adam Van Wynsberghe, Kelly Anderson, Sudeep Bhattacharyay, Jim Phillips, and Aimee Tomlinson.

”Acquisition of a High Performance Computer for the Molecular Education and Research Consortium in Undergraduate computational chemistRY (MERCURY)”  Award Number: CHE-1229354.


National Science Foundation RUI  (2011-2015)
Maria A Gomez

“Understanding how grain boundaries affect preferred proton conduction pathways in doped perovskite oxides”  Award Number: CHE-1111474


Cottrell College Science Awards (2010-2014)
Maria A. Gomez and Dylan Shepardson

“Graph Theoretic Methods to Find Conduction Pathways Through Grain Boundaries”


Dreyfus Special Grant Program in the Chemical Sciences  (2009-2016)
Maisie J. Shaw and Maria A. Gomez

“Passport to chemistry adventure for elementary school students and their parents”

Research

 

Research opportunities for Undergraduates


If you would like to apply to join our research group, email me indicating your interest and include an attachment which answers the questions below.

1. Why are you interested in doing research with our group?

2. What do you think we do?  Pick just one project (from one of our papers) and describe it in your own words.

3. What are your goals after you graduate from Mount Holyoke College? 

4. How does doing research in our group advance your goals?

5. What is your academic background?  List all the mathematics, physics, chemistry, and computer science courses you have had in college and your experience and comfort in them.

6. Is there something else in your experience that has prepared you or motivates you to do research in our group?

7. Make sure that you can commit yourself to a 4 credit independent study the first semester and subsequent 2-4 credit independent studies.  Each two credits represents a full afternoon of computer and/or paper and pencil work plus time outside of that for writing.  There are also opportunities for summer research after at least one independent study semester.  After a summer of research at Mount Holyoke, students are encouraged and assisted in finding a complementary research experience outside of Mount Holyoke to round out their experience.  To show your understanding, outline the commitment and logistics involved in doing research with our group.