Guntae Kim 교수

As part of an investigation of new cathode materials for intermediate temperature solid oxide fuel cells, we have investigated particular perovskite oxides with ordered A cations which, in turn, localize the oxygen vacancies into layers. The oxygen exchange kinetics of polycrystalline samples of the oxygen-deficient double perovskite PrBaCo2O5+x (PBCO) have been determined by electrical conductivity relaxation (ECR) and by oxygen-isotope exchange and depth profiling (IEDP). The ECR and IEDP meas

We report on an excellent anode-supported H(+) -SOFC material system using a triple conducting (H(+) /O(2-) /e(-) ) oxide (TCO) as a cathode material for H(+) -SOFCs. Generally, mixed ionic (O(2-) ) and electronic conductors (MIECs) have been selected as the cathode material of H(+) -SOFCs. In an H(+) -SOFC system, however, MIEC cathodes limit the electrochemically active sites to the interface between the proton conducting electrolyte and the cathode. New approaches to the tailoring of cathode

Abstract Solid oxide fuel cells (SOFCs) are characterized by low pollution, and are therefore the best alternative both for distributed energy sources and large‐scale integration. Fuel flexibility, including hydrocarbons, is the main advantage of SOFCs. For the successful introduction of SOFC technology to the market, reduced temperature operation at 600–800 °C is an essential factor. One of the important issues for the reduced temperature operation is to get rid of stability issues while mainta

A class of double-perovskite compounds display fast oxygen ion diffusion and high catalytic activity toward oxygen reduction while maintaining excellent compatibility with the electrolyte. The astoundingly extended stability of NdBa(1-x)Ca(x)Co2O(5+δ) (NBCaCO) under both air and CO2-containing atmosphere is reported along with excellent electrochemical performance by only Ca doping into the A site of NdBaCo2O(5+δ) (NBCO). The enhanced stability can be ascribed to both the increased electron affi

Designing a high-efficiency and low-cost three-dimensional (3D) OER electrode <italic>via</italic> electrochemical integration of amorphous NiFeOOH on surface activated carbon fibers.

Composites formed by infiltration of 45 wt % La(0.8)Sr(0.2)Cr(0.5)Mn(0.5)O(3) (LSCM) into a 65% porous yttria-stabilized zirconia (YSZ) scaffold were investigated in order to understand the reasons this material is able to provide excellent anode performance in solid oxide fuel cells (SOFCs). Scanning electron microscopy showed that the LSCM forms a film over the YSZ after calcination at 1473 K but that this film undergoes cracking to expose a long three-phase boundary after reduction at 1073 K.

Ceramic anodes for solid oxide fuel cells (SOFCs) were prepared by aqueous impregnation of nitrate salts to produce composites with 45 wt % La0.8Sr0.2Cr0.5Mn0.5O3 (LSCM ) in a 65% porous yttria-stabilized zirconia (YSZ) scaffold. Scanning electron micrographs indicate that the LSCM coats the YSZ pores following calcination at 1473 K. Composites produced in this manner exhibit conductivities at 1073 K of approximately 1 S/cm in air and 0.1 S/cm in humidified H-2. A SOFC with a composite anode com

The oxygen exchange kinetics of thin films of the oxygen-deficient double perovskite PrBaCo2O5+δ (PBCO) have been determined by electrical conductivity relaxation (ECR) and by oxygen-isotope exchange and depth profiling (IEDP). Microstructural studies indicate that the PBCO films, prepared by pulsed laser deposition, have excellent single-crystal quality and epitaxial nature. The ECR and IEDP measurements reveal that the PBCO films have high electronic conductivity and rapid surface exchange kin

Water-mediated surface self-assembly on PrBa_0.8Ca_0.2Co₂O_5+δ (PBCC) results in formation of BaCoO_3−δ (BCO) nanoparticles to boost catalytic activity of oxygen reduction, as confirmed by <italic>in situ</italic> Raman spectroscopy at high temperatures (HT).

Dry reforming of methane (DRM) is a feasible solution to address the reduction of greenhouse gases stipulated by the Paris Climate Agreement, given that it adds value by converting trivial gases, CO₂ and CH₄ , simultaneously into useful syngas. However, the conventional Ni catalyst undergoes deactivation due to carbon coking and particle agglomeration. Here we demonstrate a highly efficient and durable DRM catalyst: exsolved Co-Ni-Fe ternary alloy nanoparticles on the layer

The crystalline phase of layered transition metal dichalcogenides (TMDs) directly determines their material property. The most thermodynamically stable phase structures in TMDs are the semiconducting 2H and metastable metallic 1T phases. To overcome the low phase purity and instability of 1T-TMDs, which limits the utilization of their intrinsic properties, various synthesis strategies for 1T-TMDs have been proposed in phase-engineering studies. Herein, a facile and scalable synthesis of 1T-phase

A robust Ca doped PrBaMn₂O_5+δ with a layered perovskite shows not only good chemical and structural stability under reducing and oxidizing conditions but also remarkable electrochemical performance in hydrogen and hydrocarbon fuels for a symmetrical solid oxide fuel cells electrode.