Pyuck‐Pa Choi
Korea Advanced Institute of Science and Technology · 工学
研究室紹介
Professor Pyuck-Pa Choi's research lab specializes in advanced materials design, with a focus on nanostructured alloys, intermetallic phases, and functional nanomaterials for energy and catalytic applications. The lab investigates precipitation strengthening mechanisms in medium-entropy and high-entropy alloys, explores atomically precise catalysts for electrochemical CO2 reduction, and examines interfacial phenomena in oxide-supported catalysts using advanced characterization techniques such as atom probe tomography and operando spectroscopy. A central theme is the manipulation of atomic-scale structure and chemistry to achieve superior mechanical and electrochemical performance.
Research Overview
Research Output Trend
Figures are computed from collected data and may differ slightly.
Selected Papers
15Abstract Precipitation strengthening has been the basis of physical metallurgy since more than 100 years owing to its excellent strengthening effects. This approach generally employs coherent and nano-sized precipitates, as incoherent precipitates energetically become coarse due to their incompatibility with matrix and provide a negligible strengthening effect or even cause brittleness. Here we propose a shear band-driven dispersion of nano-sized and semicoherent precipitates, which show signifi
for the amorphous iron nanoparticles. To our knowledge, this is the highest value reported so far for Congo red adsorption. The acquired data have been evaluated applying various models for adsorption kinetics and thermodynamic studies. The isotherm models as well as acquired Fourier transform infrared spectra suggest that both chemi- and physisorption occur for Congo red adsorption on iron nanoparticles, where chemisorption appears to be dominant. The kinetics of adsorption of Congo red on both
Novel Cr containing Co-Al-W base superalloys were studied by atom probe tomography and neutron diffraction. Cr is found to predominantly partition to the γ matrix and decrease partitioning of W to γ′. Furthermore, Cr significantly enhances the γ′ volume fraction, decreases the γ/ γ′ lattice misfit and deteriorates the creep resistance. Addition of Ni to the Cr containing alloys affects partitioning of W and Al, further decreases the lattice misfit and results in the formation of irregularly shap
Ceria (CeO 2 ) is one of the most extensively used rare earth oxides. Recently, it has been used as a support material for metal catalysts for electrochemical energy conversion. However, to date, the nature of metal/CeO 2 interfaces and their impact on electrochemical processes remains unclear. Here, a Cu–CeO 2 nanorod electrochemical CO 2 reduction catalyst is presented. Using operando analysis and computational techniques, it is found that, on the application of a reductive electrochemical pot
The development of Cu-based catalysts for electrochemical CO 2 reduction reaction (CO 2 RR) with stronger CO-binding elements had been unsuccessful in improving multicarbon production from the CO 2 RR due to CO-poisoning. Here, we discover that trace doping levels of Co atoms in Cu, termed CoCu single-atom alloy (SAA), achieve up to twice the formation rate of CO as compared to bare Cu and further demonstrate a high j C 2 H 4 of 282 mA cm –2 at −1.01 V RHE in a neutral electrolyte. From DFT calc
We report on a comparative study of Cu(In,Ga)Se2 solar cells deposited on soda-lime glass and mild steel substrates, using atom probe tomography in conjunction with secondary ion mass spectrometry, x-ray fluorescence, current density-voltage, and external quantum efficiency measurements. Cu(In,Ga)Se2 films deposited on soda-lime glass substrates and on steel substrates with a NaF precursor layer on top of the Mo back contact contain a significant amount of Na impurities and yield an enhanced ope