Graduate Student
Email: dsrivas@ncsu.edu
Office: 2029 Engineering Building 1
Phone: (919) 513-2051
Education
B.S. Chemical Engineering, The University of Texas at Austin, 2011
M.S. Chemical Engineering, North Carolina State University, 2015
Research Interests
Modeling and simulation of chemical reactions in confinement
It is well established that confinement within a nano-porous material, such as an activated carbon, carbon nanotube, or porous oxide can affect reaction yield, reaction rate and even the mechanism of the reaction [1,2]. These effects arise from the strong intermolecular forces between the various reacting species, including the activated state, and the pore walls, but are poorly understood.
We use Reactive Monte Carlo (RxMC) simulations to study the effects of confinement within a nanoporous carbon material on the equilibrium yield of the nitric oxide dimerization reaction, 2NO=(NO)2. This reaction is chosen for study both because of its importance in atmospheric chemistry and biology, and because experimental data is available for the effect of confinement within carbon materials. Thus Kaneko and coworkers [3] have used magnetic susceptibility measurements to determine the equilibrium yield of the dimer in activated carbon fibers having slit-shaped pores of 0.8 nm width, while Yates and coworkers [4] have used FTIR spectra to find the yield in single-walled carbon nanotubes of diameter 1.35 nm. At the experimental conditions the yield of dimer in the gas phase in equilibrium with the pore phase was less than 1 mol %, whereas the yield within the pores was 100 mol % within the accuracy of the experiment. Monte Carlo simulations reported [5] in 2001 found a large increase in the yield within slit-shaped pores due to the confinement, but the calculated yield was well below the experimental value.
[1] C.H. Turner, J.K. Brennan, M. Lisal, W.R. Smith, J.K. Johnson and K.E. Gubbins, “Simulation of Chemical Reaction Equilibria by the Reaction Ensemble Monte Carlo Method: A Review”, Molecular Simulation, 34, 119-146 (2008).
[2] C.H. Turner, J.K. Brennan, J.K. Johnson and K.E. Gubbins, “Effect of Confinement by Porous Materials on Chemical Reaction Kinetics”, Journal of Chemical Physics, 116, 2138-2148 (2002).
[3] K. Kaneko, N. Fukuzaki, K. Kakei, T. Suzuki and S. Ozeki, Langmuir, “Enhancement of NO Dimerization by Micropore Fields of Activated Carbon Fibers”, 5, 960-965 (1989).
[4] O. Byl, P. Kondratyuk and J. T. Yates, “Adsorption and Dimerization of NO inside Single-Walled Carbon Nanotubes – An Infrared Spectroscopic Study”, J. Phys. Chem. B, 2003, 107, 4277-4279.
[5] C. H. Turner, J. K. Johnson and K. E. Gubbins, “Effect of Confinement on Chemical Reaction Equilibria: The Reactions 2NO = (NO)2 and N2+3H2 = 2NH3 in Carbon Micropores”, J. Chem. Phys., 114, 1851-1859 (2001).