top of page
본 사이트는
.com
사이트 제작 도구로 제작되었습니다. 지금 나만의 사이트를 만들어보세요.시작하기

Research topics

Research Interest

​   Energy Production and Recovery

  • White ammonia recovery by PBAs

  • Fuel cell: oxygen reduction reaction

  • H2 storage and dehydrogenation

  • CO2 conversion to fuels

  • Hydrogen evolution reaction

​   Environmental Pollution Cleanup

  • Cesium (Cs) removal by PBAs

  • Pollutant chemical decomposition 

  • Fe-based oxide oxidation

  • Cl2 evolution reaction

Durable titanium nitride (TiN) electrocatalyst supports

Transition metal nitrides possessing superior electrical conductivity and outstanding oxidation and corrosion resistance have been described as good substitutes for carbon support materials which are vulnerable during proton exchange membrane fuel cell (PEMFC) operation due to corrosion and poor life cycles. A closer theoretical inspection of the stability and electronic properties of titanium nitride supported Pt in comparison with carbon-supported Pt (using graphite and graphene) has been conducted using density functional theory calculations. A single Pt atom adsorbed more strongly to the TiN surface than to both graphite and graphene, causing a larger degree of charge transfer between Pt and TiN. 

(J. Ind. Eng. Chem., 2017, 49, 69)  

CO2 Conversion into Hydrocarbon Fuels 

Density functional theory studies demonstrate that defective grapheme-supported Cu nanoparticles can modify the structural and electronic properties of copper for enhancing electrochemical reduction of carbon dioxide (CO2) into hydrocarbon fuels (CH4, CO, and HCOOH). We not only provide improved understanding of CO2 conversion mechanisms on both Cu and the Cu nanoparticle system, but also explain a key factor for enhanced CO2 conversion. A promising catalytic material for CO2 conversion into hydrocarbon fuels may allow for geometry flexibility upon interaction with a key intermediate of CHO*.

(Nanoscale, 2014, 6(10), 5087)  

Solid Oxide Fuel Cells (SOFCs) with Sm-doped CeO2

The role of samarium (Sm) 4f states and Sm-perturbed O 2p states in determining the sulfur tolerance of Sm-doped CeO2 was elucidated by using the density functional theory (DFT)+U calculation. We find that the sulfur tolerance of Sm-doped CeO2 is closely related to the modification of O 2p states by the strong interaction between Sm 4f and O 2p states. In particular, the availability of unoccupied O 2p states near the Fermi level is responsible for enhancing the sulfur tolerance of Sm-doped CeO2 compared to the pure CeO2 by increasing the activity of surface lattice oxygen toward sulfur adsorbate, by weakening the interaction between Sm–O, and by increasing the migration tendency of subsurface oxygen ion toward the surface.

(Phys. Chem. Chem. Phys., 2014, 16(22), 10727) 

Oxygen Reduction Reaction on Graphene-Pt Nanoparticles

The mechanisms of the oxygen reduction reaction (ORR) on defective graphene-supported Pt13 nanoparticles have been investigated to understand the effect of defective graphene support on the ORR and predict details of ORR pathways. We demonstrate that the defective graphene support may provide a balance in the binding of ORR intermediates on Pt13nanoparticles by tuning the relatively high reactivity of free Pt13 nanoparticles that bind the ORR intermediates too strongly subsequently leading to slow kinetics. The defective graphene support lowers not only the activation energy for O2 dissociation from 0.37 to 0.16 eV, but also the energy barrier of the rate-limiting step by reducing the stability of HO* species. 

(J. Phys. Chem. C., 2012, 116(5), 3653) 

Mercury (Hg(0)) Adsorption and Oxidation on Gold (Au)

Density functional theory (DFT) studies of mercury oxidation on Au(111) are conducted to determine the potential Hg oxidation mechanisms taking place on catalytic gold surfaces by using the Perdew and Wang approximation (PW91) described by a generalized gradient approximation (GGA). The Climbing Image-Nudged Elastic Band (CI-NEB) method has been employed to calculate the activation energies of HgCl and HgCl2 formation pathways (a Langmuir–Hinshelwood mechanism). In the three-step Hg oxidation mechanism (Hg → HgCl → HgCl2), the second Cl attachment step is endothermic which is the reaction rate-limiting step, while the first Cl attachment step is exothermic. This observation implies that Hg oxidation prefers a pathway in which HgCl and HgCl2are formed, rather than a pathway directly oxidizing Hg to HgCl2. 

(Environ. Sci. Technol., 2013, 47(15), 8515)

Chloroethene Reduction on Zerovalent Iron (Fe(0))

The gas-phase dissociation of perchloroethene (PCE), trichloroethene (TCE), andcis-dichloroethene (cis-DCE) on zerovalent iron Fe(110) was investigated using periodic density functional theory (DFT) with the generalized gradient approximation (GGA) and climbing image nudged elastic band method (CI-NEB). Activation energies were found to decrease as the chlorination number increases. The activation energies of PCE, TCE, and cis-DCE at their rate-limiting steps are 9.9, 16.6, and 23.8 kJ/mol, respectively. The relative gas-phase reactivity order among chlorothenes on Fe(110) was found to be PCE > TCE > cis-DCE. At room temperature (300 K), the PCE dechlorination rate is 14 and 338 times faster, respectively, than that of TCE and cis-DCE.

(Environ. Sci. Technol., 2009, 43(14), 5443)

Dept. of Environmental Engineering, Chungbuk National University

Cheongju, Chungbuk, KOREA (South)

bottom of page