Jungki Ryu

Measuring pH Changes Inside a Bipolar Membrane Junction The local pH environment within bipolar membrane (BPM) junctions is complex and not well understood, yet it is important to control for advancing the performance of BPM-based electrochemical systems. We report a voltammetric strategy using an ultrathin Ni mesh pH probe to spatially resolve pH changes in the BPM junction during model BPM electrolyzer operation. Under reverse bias, we observe depletion of OH– at the anion-exchange layer (AEL) interface, with a degree diminishing with increasing distance from the AEL. These gradients correlate with current-dependent water dissociation (WD) and are modulated by the electric field and the surface charge state of the catalyst. By correlating spatial pH profiles with the surface-charging behavior of WD catalysts, we explore a mechanism of catalyst-mediated H+ and OH– transfer facilitated by hydrogen-bonding networks. These findings highlight the role of local chemistry and electrostatics in BPM performance and offer new methods to probe and engineer catalytic junctions in electrochemical energy devices.

Just published from @boettcherlab.bsky.social
Measuring pH Changes Inside a Bipolar Membrane Junction | ACS Energy Letters pubs.acs.org/doi/10.1021/...

🎉 Our work is featured as a Cover Article in Advanced Science!
Anisotropically wettable PTLs enable efficient gas–liquid management, suppress interfacial blockage, and achieve stable, bubble-free electrolysis at high current densities.
🔗 advanced.onlinelibrary.wiley.com/doi/10.1002/...

New paper accepted in J. Mater. Chem. A 🎉
Subsurface W⁵⁺/W⁶⁺ redox takes over the oxidation cycle in metal tungstate OER catalysts.
pubs.rsc.org/en/Content/A...
#OER #Electrocatalysis #MaterialsChemistry

Group photo from the KECS Fall Meeting in Busan.
Thanks to everyone for the engaging talks and discussions. #KECS #FallMeeting #Busan #Electrochemistry

🎉 The UNIST Electrochemistry Pioneer Symposium 2025 was successfully concluded! Huge thanks to all speakers, participants, the organizing committee, staff, and our sponsors. See you again next year!
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Thrilled to share our new study in Advanced Science ✨
in collaboration with Prof. Dong Woog Lee. A simple PTFE spray on Ni foam enables anisotropically wettable porous transport layers for directing gas–liquid flow in water electrolyzers 💧⚡🔗 doi.org/10.1002/advs...

The 1st UNIST Electrochemistry Pioneers Symposium 2025 / 📅 Nov 13–14 /📍 UNIST, Ulsan, Korea. World-leading researchers from Stanford, Princeton, Georgia Tech, UC San Diego, UT Austin & UNIST will gather to discuss innovation in electrochemistry. #Electrochemistry #EnergyConversion #UNIST