Featured Researchers

Dr. Babu Joseph - Multiscale Modeling and Simulation

Multiscale Modeling and Simulation

Dr. Babu Joseph, Professor of Chemical Engineering, and his team work in the areas of modeling and simulation applied to a wide variety of problems ranging from the production of liquid fuels from biomass to the capture of solar energy using novel photocatalytic systems. At the macroscale they are interested in modeling and simulation of large scale reactors and separation systems using computational tools such as Matlab, ASPEN and CHEMCAD. His group is also investigating the properties of nanoscale systems such as nanosized bimetallic catalyst particles using modeling tools such as DL-POLY. At the molecular and electronic scale they are interested in modeling the energetics of reactions taking place on a catalyst surface using applications for Density Functional Theory (DFT) simulation. These simulations enable them to speed up the discovery of novel catalytic systems for solar energy conversion, renewable energy production and large scale energy storage systems.

The next Research Computing User's Group Forum, on October 24th, 2013 @ 3:30pm in the Advanced Visualization Center, will feature a talk from Chi-Ta Yang, a doctoral student in Dr. Joseph's lab group, titled "Subnanometer Ag and Pt clusters adsorbed on anatase TiO2(101) surfaces: Implications for Catalysis and CO2 Photoreduction." Dr. Joseph will also be in attendance to answer questions and discuss his group's research. They will review some of their recent efforts in the area of Computational Catalysis. Advances in computing power, combined with the development of computationally efficient methods to compute electronic structure of molecules allow them to investigate reaction mechanisms occurring on catalyst surfaces. This in turn has enabled the ability to screen potential new catalysts for achieving selectivity and yield objectives. These types of complex calculations are done using DFT simulation software, such as VASP and GAUSSIAN, which utilize the high-performance computing (HPC) resources available and supported by the Research Computing staff at the University of South Florida. Simulation studies also enable the prediction of possible reaction mechanisms, and hence the development of kinetic models for reactor design and scale-up.

Chi-Ta Yang's research utilizes Density Functional Theory simulation software such as VASP and Gaussian to gain insights into Catalysis and Photocatalysis (Figure 1). He studies the interactions of CO2, subnanometer Ag/Pt clusters, and anatase TiO2(101) surfaces to understand the design of efficient catalyst and photocatalyst for CO2 photoreduction. For the catalysis part, his goal is to investigate the binding mechanism, and gain catalytic insights. For the CO2 photoreduction part, the sub-bandgap creation and the first (and key) step of the CO2 photoreduction mechanism (CO2 to form CO2¯ radical) are studied in the presence of subnanometer clusters. The first and key step in the study relies on the geometry of the adsorbed CO2 on the model surface. As the bond angle of the adsorbed CO2 is increasingly bent, the easier the transfer of photoexcited electrons to CO2 to form the CO2¯ anion radical becomes. Shown in Figure 1, the Pt octamer offers additional adsorption sites for the bent form of CO2 at the interface and on the Pt octamer. Overall, the goal of his research is to provide a better understanding that would be helpful in the design of the subnanometer cluster based catalysts and photocatalysts.

 Figure 1

 Electronic Structure Calculations