CR1220 battery

Researchers Uncover Secrets of Catalysts that Improve Efficiency of Fuel-Powered CR1220 battery 4 Times More Powerful Than Conventional Catalysts

Fuel cells are gaining attention as an environmentally friendly energy source that simultaneously obtains electricity and heat through the reverse reaction of water electrolysis. Therefore, catalysts that improve reaction efficiency are directly related to the performance of fuel cells. To this end, the POSTECH-UNIST joint research team has taken a step toward developing high-performance catalysts by discovering the phenomenon of dissolution and phase transition at the atomic level for the first time.

Candidate Kyeounghak Kim of the Department of Chemical Engineering at POSTECH and Professor Guntae Kim of UNIST discovered the mechanism by which PBMO, a catalyst for fuel cells, transforms from a perovskite structure to a layered structure with nanoparticles ex-solution1 to the surface, and confirmed its mechanism, potential as an electrode and chemical catalyst. These research results were recently published as the cover of Energy and Environmental Science, an international journal in the field of energy.

Schematic diagram of the process of material phase transition, pre-solution particle formation, and catalytic activity change depending on the reducing environment.

Co-doped Pr0.5Ba0.5MnO3−δ (PBMCO) was studied by using density functional theory calculations and in situ X-ray diffraction spectroscopy experiments to understand how the phase transition from PBMCO to layered PBMCO occurs. The role of the Co dopant in the phase transition and dissolution was also elucidated. It turns out that the selective formation of oxygen vacancies on the Pr layer plays a key role in the phase transition to layered perovskite. Dissolved Co nanoparticles showed higher catalytic activity than doped Co nanoparticles. These results can guide the design of highly active perovskite-based redox catalysts.

Catalysts are substances that enhance chemical reactions. PBMO (Pr0.5Ba0.5MnO3-δ), one of the catalysts for fuel cells, is a material that can operate stably even when used directly as a hydrocarbon instead of hydrogen. In particular, under a reducing environment where oxygen is lost, it shows high ion conductivity due to the change to a layered structure. At the same time, precipitation can also occur, in which elements inside the metal oxide segregate to the surface.

This phenomenon occurs automatically without any special process under a reducing environment. When elements inside the material rise to the surface, the stability and performance of the fuel cell are greatly improved. However, it is difficult to design materials because the process of forming these high-performance catalysts is unknown.

Focusing on these functions, the research team confirmed that the process went through phase transition, particle desorption, and catalyst formation. This was demonstrated using first-principles calculations based on quantum mechanics and in-situ XRD2 experiments that can observe real-time crystal structure changes in the material. The researchers also confirmed that the oxidation catalyst developed in this way showed four times higher performance than conventional catalysts, proving that the research is applicable to a variety of chemical catalysts.

We were able to accurately understand the atomic unit materials that were difficult to confirm in previous experiments and successfully demonstrated this, thus overcoming the limitations of existing research and successfully demonstrating them, Professor Zheng Yuhan, who led the research, explained that since these support materials and nanocatalysts can be used to reduce exhaust gas, sensors, fuel cells, chemical catalysts, etc., active research is expected in many fields in the future.

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