Do-Young Kim

Octahedral Pt-Pd alloy catalysts with enhanced oxygen reduction activity and stability in proton exchange membrane fuel cells

Structure-controlled Pt-based catalysts have been known to exhibit improved electrocatalytic activities due to particularly modulated surface structures favorable for hydrogen oxidation or oxygen reduction reactions. We prepare octahedral Pt-Pd alloy nanoparticles such as Pt3Pd1, Pt1Pd1, Pt1Pd3 by reducing metal ions with glycerol as a reducing agent in an aqueous solution. The octahedral Pt-Pd nanoparticles are well-defined alloy nanostructures with dominant {111} facets. Among them, the octahedral Pt3Pd1 shows excellent electrochemical properties i.e., much enhanced electrocatalytic activity and stability for oxygen reduction reactions in comparison with conventional Pt-based catalysts.

Monodispersed platinum nanocubes for enhanced electrocatalytic properties in alcohol electrooxidation

We report Pt nanocubes of ∼4.5 nm in size synthesized by thermal decomposition in the presence of PVP. The Pt cubic electrocatalysts with dominantly exposed {100} facets show much improved electrocatalytic activities in methanol, ethanol and formic acid electrooxidation.

3-Dimensional TiO2 nanostructure supports and their improved electrochemical properties in methanol electrooxidation

The TiO2 nanostructure support consists of backbones and branches of a rutile phase forming a 3-dimensional structure with high specific surface area. The Pt catalysts on the TiO2 nanostructure supports exhibit much improved electrocatalytic activity and stability toward methanol electrooxidation in comparison with conventional Pt/C.

Reduction of NO with Fe(II) and subsequent regeneration of Fe(II) in a fuel cell

We report complete reduction reaction of NO into N2 by oxidizing Fe2+ into Fe3+. To regenerate Fe2+ as a NO absorbent from Fe3+, the H2–Fe3+ fuel cell supplied by Fe3+-containing solution at the cathode is utilized producing maximum power density of 110 mW cm−2 at 70 °C.

TiO 2 @carbon Core-Shell Nanostructure Electrodes for Improved Electrochemical Properties in Alkaline Solution

We report nanostructure electrodes with as a core and carbon as a shell (@C) for oxygen reduction in alkaline solution. The structure of core-shell electrodes is characterized by transmission electron microscopy, Raman spectroscopy, X-ray diffraction method, and X-ray photoelectron microscopy. The electrochemical properties of the @C electrodes are characterized using a potentiostat and compared with those of carbon supported Pt catalyst. In particular, the core-shell electrode with dominant pyridinic-N component exhibits an imporved electrocatalytic activity for oxygen reduction reaction in alkaline solution.