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In the face of growing energy demands and the imperative for renewable solutions, the development of
efficient electrochemical devices is essential. Such devices can convert intermittent renewable electricity
into storable fuels, such as hydrogen, via water electrolysis. Currently, noble metal catalysts like Pt for the
hydrogen evolution reaction (HER) and IrO2/RuO2 for the oxygen evolution reaction (OER) serve as
benchmarks for water splitting due to their high activity. However, the high cost and scarcity of these
materials hinder widespread adoption. Moreover, reported earth-abundant catalysts often suffer from
insufficient catalytic performance and poor durability under operational conditions. Therefore, developing
cost-effective and efficient alternatives to noble metals for HER and OER is critical for advancing green
hydrogen production technologies.
My presentation will delve into the evolution of catalytic materials, from nanostructured systems to
atomically dispersed metal single-atom catalysts (SACs), with a focus on their role in water electrolysis. I
will briefly introduce my early research during my Master's at IISER-K, where I worked on transition
metal-based nanomaterials, including porous NiFe oxide nanocubes as bifunctional catalysts for both HER
and OER, and NiFe alloy supported on biomass derived carbon support for solar light-driven water
photolysis.1,2 These efforts laid the groundwork for my Ph.D. research, which concentrated on SACs. At
Sungkyunkwan University (SKKU), I developed Ru single atoms stabilized on CoFe alloys for OER, NiCo
single-atom dimers for HER across all pH conditions, and a strategy to stabilize ultra-high loadings of
metal single atoms on oxide supports, significantly improving catalyst performance and stability.3-5
Through advanced techniques such as microscopy, spectroscopy, and electrochemical analysis, structure-
property relationships have been established to understand activity, selectivity, and durability in these
systems.
I will conclude with insights from my postdoctoral research at the Max-Planck-Institut für
Kohlenforschung (MPI-KOFO), where I have been working on stabilizing Ir single-atom catalysts on metal
oxide supports for improving their stability during OER in both alkaline and acidic oxidative conditions.
6,7
Emphasizing the mechanistic understanding gained through operando X-ray absorption spectroscopy and
in-situ Raman studies, these recent advancements pave the way for more durable and efficient catalysts
under harsh oxidative conditions.
This presentation will offer a comprehensive overview of cutting-edge approaches in electrocatalysis,
with a particular emphasis on SACs and their transformative potential in renewable energy technologies.
References:
(1) A. Kumar & S. Bhattacharyya. ACS Appl. Mater. Interfaces, 2017, 9, 41906.
(2) A. Kumar & S. Bhattacharyya et al. J. Mater. Chem. A, 2018, 6, 18948.
(3) A. Kumar & H. Lee et al. Energy Environ. Sci., 2020, 13, 5152.
(4) A. Kumar & H. Lee et al. Nature Commun., 2021, 12, 6766.
(5) A. Kumar & H. Lee et al. Energy Environ. Sci., 2021, 14, 6494.
(6) A. Kumar & H. Tüysüz et al. J. Am. Chem. Soc. 2024, DOI: 10.1021/jacs.4c08847.
(7) A. Kumar & H. Tüysüz et al. Adv. Mater. 2024, 2401648. |