Science Success Story
Computational Materials Scientists Use XSEDE Resources for Hydrogen Peroxide Synthesis
Supercomputer simulations illustrate how hydrogen peroxide is synthesized in a new way
Kimberly Mann Bruch, SDSC Communications
|This image showcases a critical intermediate during oxygen reduction to hydrogen peroxide. Credit: Xunhua Zhao and Yuanyue Liu, UT Austin|
Hydrogen peroxide, often used as a disinfectant, serves as a precursor for many organic compounds. Recently, computational materials scientists at The University of Texas Austin (UT Austin) investigated a novel synthetic approach where oxygen molecules react with water and electrons with the help of a catalyst, such as a cobalt atom bound to four nitrogen atoms and embedded in a thin layer of carbon (Co-N4-C), to form hydrogen peroxide.
However, the scientists were puzzled about how and why the reaction produced hydrogen peroxide (H2O2) rather than hydroxide (HO-), which was expected due to its lower energy. To answer this question, they used XSEDE-allocated supercomputing resources to simulate the reaction at an atomic scale.
Yuanyue Liu, an assistant professor of materials science and engineering, and Xunhua Zhao, a postdoctoral researcher, used Comet at the San Diego Supercomputer Center (SDSC) at the University of California at San Diego (UC San Diego) and Stampede2 at the Texas Advanced Computing Center (TACC) at UT Austin, to detail how oxygen molecules react with water and electrons to form hydrogen peroxide on the catalyst.
Liu and Zhao recently published their study results in the Journal of American Chemical Society.
Prior to these simulations, there was limited understanding about why some catalysts yield more hydrogen peroxide than hydroxide, due to the lack of an effective tool to simulate the kinetics.
"XSEDE provided computational resources without which we would not be able to do our research," Zhao said. "Using Comet and Stampede2 to simulate this reaction, we found that bond breaking to yield hydrogen peroxide can have a lower energy barrier than the bond breaking to yield hydroxide, despite that the hydroxide has a lower energy than the hydrogen peroxide."
"Moreover, we explained why the yield of hydrogen peroxide increases with decreasing electrode potential," Liu said. "There are two types of oxygen in the reaction and depending on which one first gets hydrogen from water, you may obtain different products – decreasing the electrode potential pushes the water closer to the oxygen and that will give us hydrogen peroxide."
Why It's Important
Liu and Zhao's findings have helped the materials science community further understand this important fundamental process; however, there is much work to be done.
"While our research uncovers how hydrogen peroxide is selectively produced, we continue to work on making our simulations less computationally expensive," Liu said. "We are also working on applying this model to other electrochemical systems."
How XSEDE Helped
"We used XSEDE resources to first develop an advanced first-principles model for effective calculations of the electrochemical kinetics at the solid-water interface," Liu said. "Then, we used Comet and Stampede2 to simulate the pathways of forming hydrogen peroxide and hydroxide on the Co-N4-C catalyst, and how these pathways vary with the applied electrode potential – this allowed us to understand what makes one product more favorable than the other, and how to tune the preference."
"We look forward to working on Expanse at SDSC for our next set of simulations that will help us continue developing and applying atomistic modelling methods to understand, design, and discover materials for electronics and energy applications." – Yuanyue Liu, assistant professor at UT Austin's Materials Science and Engineering Department
Zhao and Liu said that while they ran into a few code compilation problems during their study, XSEDE support was helpful in assisting with solutions.
"We look forward to working on Expanse at SDSC for our next set of simulations that will help us continue developing and applying atomistic modeling methods to understand, design, and discover materials for electronics and energy applications," Liu said.
This work was supported by the National Science Foundation (awards 1900039 and 2029442), the Welch Foundation (F-1959-20180324), ACS PRF (60934-DNI6), and the Department of Energy (DE-EE0007651). This work used computational resources at National Renewable Energy Lab, XSEDE (allocation TG-CHE190065), the Center for Nanoscale Materials at Argonne National Laboratory and the Center for Functional Nanomaterials at Brookhaven National Laboratory.
San Diego Supercomputer Center: https://www.sdsc.edu/
Texas Advanced Computing Center: https://tacc.utexas.edu/
UC San Diego: https://ucsd.edu/
University of Texas at Austin: https://utexas.edu/
National Science Foundation: https://www.nsf.gov/
At a Glance:
- UT Austin researchers used XSEDE resources to illustrate a detailed model of oxygen molecules reacting with water and electrons to form hydrogen peroxide on the catalyst.
- Study results were published in the Journal of American Chemical Society.
- The scientists will next utilize Expanse at the San Diego Supercomputer Center for additional modelling to further their research.