Publications de Seunghwa Lee | EPFL Graph Search

Operando Nanoscale Characterization Reveals Fe Doping of Ni Oxide Enhances Oxygen Evolution Reaction via Fragmentation and Formation of Dual Active Sites

Magalí Alejandra Lingenfelder, Xile Hu, Karla Banjac, Seunghwa Lee, Yunchang Liang, Victor Carle Adrien Boureau

Efficient catalytic water splitting demands advanced catalysts to improve the slow kinetics of the oxygen evolution reaction (OER). Earth-abundant transition metal oxides show promising OER activity in alkaline media. However, most experimental information ...

2025

High entropy molybdate-derived FeOOH catalyzes oxygen evolution reaction in alkaline media

Lichen Bai, Seunghwa Lee

High-entropy materials are a new class of materials that have lately been developed and applied to a variety of potential fields. Here we present that electrochemical activation facilitates the application of high-entropy molybdates (HEMo) as oxygen evolut ...

PERGAMON-ELSEVIER SCIENCE LTD2023

Operando identification of a side-on nickel superoxide intermediate and the mechanism of oxygen evolution on nickel oxyhydroxide

Xile Hu, Lichen Bai, Seunghwa Lee

The oxygen evolution reaction (OER) is a key electrochemical reac-tion relevant to energy storage. Ni-containing bimetallic oxyhydrox-ides are among the most active OER catalysts in alkaline medium, but the mechanism of OER on pure Ni oxyhydroxide remains ...

ELSEVIER2023

Synergistic interactions between PtRu catalyst and nitrogen-doped carbon support boost hydrogen oxidation

Andreas Schueler, Jeremy Luterbacher, Xile Hu, Anna Krammer, Weiyan Ni, Lichen Bai, Miyeon Chang, Seunghwa Lee, Songlan Sun, Seongmin Jin, Yiwei Zheng

Hydroxide exchange membrane fuel cell (HEMFC) is a potentially cost-effective energy conversion technology. However, current state-of-the-art HEMFCs require a high loading of platinum-group-metal (PGM) catalysts, especially for the hydrogen oxidation react ...

NATURE PORTFOLIO2023

Enhancement of electrocatalytic oxygen evolution by chiral molecular functionalization of hybrid 2D electrodes

Magalí Alejandra Lingenfelder, Xile Hu, Karla Banjac, Seunghwa Lee, Yunchang Liang

While solar-to-fuel catalysis requires the careful transfer of electrons, there are still challenges understanding how electron spin contributes to reactivity. Here, authors employ chiral fused thiadiazole-helicenes to control spin polarization in oxygen e ...

Nature Portfolio2022

An efficient nickel hydrogen oxidation catalyst for hydroxide exchange membrane fuel cells

Andreas Schueler, Jeremy Luterbacher, Xile Hu, Anna Krammer, Florent Emmanuel Héroguel, Weiyan Ni, Liang Yao, Seunghwa Lee

Hydroxide exchange membrane fuel cells are promising as an energy conversion technology, but require platinum group metal electrocatalysts for their application. A Ni-based hydrogen oxidation reaction catalyst is now shown to exhibit unprecedented electroc ...

2022

Tracking high-valent surface iron species in the oxygen evolution reaction on cobalt iron (oxy)hydroxides

Xile Hu, Aliki Moysiadou, Seunghwa Lee

The oxygen evolution reaction (OER) is the bottleneck reaction of water splitting, which can be used to generate green hydrogen from renewable electricity. Cobalt iron oxyhydroxides (CoFeOxHy) are among the most active OER catalysts in alkaline medium. How ...

2022

Spectroscopic and Electrokinetic Evidence for a Bifunctional Mechanism of the Oxygen Evolution Reaction**

Xile Hu, Lichen Bai, Seunghwa Lee

A bifunctional oxygen evolution reaction (OER) mechanism, in which the energetically demanding step of the attack of hydroxide on a metal oxo unit is facilitated by a hydrogen atom transfer to a second site, has the potential to circumvent the scaling rela ...

Wiley-VCH Verlag GmbH2021

Mechanism of Oxygen Evolution Catalyzed by Cobalt Oxyhydroxide: Cobalt Superoxide Species as a Key Intermediate and Dioxygen Release as a Rate-Determining Step

Xile Hu, Aliki Moysiadou, Seunghwa Lee

The oxygen evolution reaction (OER) is the performance-limiting half reaction of water splitting, which can be used to produce hydrogen fuel using renewable energies. Whereas a number of transition metal oxides and oxyhydroxides have been developed as prom ...

2020

Deciphering Iron-Dependent Activity in Oxygen Evolution Catalyzed by Nickel-Iron Layered Double Hydroxide

Xile Hu, Lichen Bai, Seunghwa Lee

Nickel iron oxyhydroxide is the benchmark catalyst for the oxygen evolution reaction (OER) in alkaline medium. Whereas the presence of Fe ions is essential to the high activity, the functions of Fe are currently under debate. Using oxygen isotope labeling ...

Wiley-VCH Verlag GmbH2020

Oxygen Isotope Labeling Experiments Reveal Different Reaction Sites for the Oxygen Evolution Reaction on Nickel and Nickel Iron Oxides

Magalí Alejandra Lingenfelder, Xile Hu, Karla Banjac, Seunghwa Lee

Nickel iron oxide is considered a benchmark nonprecious catalyst for the oxygen evolution reaction (OER). However, the nature of the active site in nickel iron oxide is heavily debated. Here we report direct spectroscopic evidence for the different active ...

Wiley-VCH Verlag GmbH2019

Transition Metal Oxides as Electrocatalysts for the Oxygen Evolution Reaction in Alkaline Solutions: An Application-Inspired Renaissance

Xile Hu, Laurent Liardet, Fang Song, Aliki Moysiadou, Lichen Bai, Seunghwa Lee, Chao Hu

Water splitting is the essential chemical reaction to enable the storage of intermittent energies such as solar and wind in the form of hydrogen fuel. The oxygen evolution reaction (OER) is often considered as the bottleneck in water splitting. Though meta ...

2018