CeNS Innovates Iron-Enhanced Catalyst for Clean Oxygen Electrocatalysis

The journey began with the use of metal-organic frameworks (MOFs)—porous crystalline structures known for their high surface area and tailorability.

A groundbreaking innovation from the Centre for Nano and Soft Matter Sciences (CeNS), an autonomous institute under the Department of Science and Technology (DST), Bengaluru, is set to transform the field of clean energy. Researchers at CeNS have engineered a next-generation catalyst that promises to drastically improve the speed, cost-efficiency, and sustainability of vital oxygen-based catalytic reactions at the core of green technologies.

Addressing the Catalyst Conundrum in Clean Energy

Electrocatalysis—facilitating chemical reactions using electricity—is fundamental to various clean energy processes such as water splitting to generate hydrogen, synthesis of hydrogen peroxide, and fuel cell operations. However, the widespread use of these technologies has long been hindered by challenges like sluggish reaction kinetics, high overpotentials, and the reliance on expensive and rare metals such as platinum and ruthenium.

These precious metals, while effective, contribute significantly to the operational costs of clean energy systems, creating economic barriers to large-scale adoption. Recognizing the urgent need for alternatives, the CeNS team has developed an iron-doped nickel selenide catalyst that not only addresses the cost issue but also demonstrates superior catalytic performance.

A Novel Approach: Iron Doping in Nickel Selenide

The journey began with the use of metal-organic frameworks (MOFs)—porous crystalline structures known for their high surface area and tailorability. However, MOFs are typically poor conductors of electricity, limiting their direct utility in electrocatalysis.

To overcome this limitation, the CeNS researchers thermally treated MOFs through pyrolysis to transform them into conductive, carbon-rich frameworks. This conversion retained the structural benefits of MOFs while imparting essential conductivity. Selenium was then introduced into the structure to form complex nickel selenides, and a precise quantity of iron (Fe) was doped into the nickel sites to fine-tune the catalyst’s electronic structure.

The result was the development of two distinct iron-enhanced catalysts—NixFe1−xSe₂–NC and Ni₃−xFexSe₄–NC. The most effective variant, NixFe1−xSe₂–NC@400, showcased remarkable dual-function performance for both the Oxygen Evolution Reaction (OER) and Oxygen Reduction Reaction (ORR).

Enhanced Performance in Key Reactions

In OER testing, where water is split to generate oxygen and hydrogen, the newly developed catalyst displayed a much lower overpotential compared to conventional ruthenium-based catalysts, meaning it required significantly less energy to initiate and sustain the reaction. Moreover, the catalyst demonstrated extraordinary long-term durability, maintaining high performance over 70 continuous hours of operation.

In ORR testing—crucial for hydrogen peroxide production and fuel cells—the same catalyst outperformed industry-standard platinum-based catalysts. It achieved higher reaction rates and better selectivity, indicating its superior capacity for facilitating the reduction of oxygen into chemical products.

The Role of Iron: Structural and Electronic Enhancements

The key to this success lies in the strategic introduction of iron. Iron doping was found to beneficially alter the catalyst’s electronic structure, increasing the number of catalytically active sites and enhancing the electronic interactions within the material. This modification enabled improved electron transport—a critical factor for accelerating reaction rates in electrocatalytic systems.

Furthermore, the selenium-rich matrix stabilized the catalyst’s structure, helping maintain consistent performance under high-stress conditions. The presence of carbon, derived from pyrolyzed MOFs, further boosted conductivity and structural resilience.

Implications for Clean Energy and Industry

This discovery marks a significant leap toward the development of scalable, affordable, and efficient catalysts for clean energy applications. By replacing scarce and costly noble metals with abundant elements like nickel, iron, and selenium, the CeNS innovation holds promise for drastically reducing operational costs in industrial processes involving electrolysis and fuel cells.

Industries ranging from renewable hydrogen production to chemical manufacturing and energy storage stand to benefit. More importantly, the environmentally friendly nature of the new catalyst aligns with global goals to decarbonize energy and reduce reliance on fossil fuels.

Future Directions: Towards Custom-Designed Catalysts

Published in the esteemed journal Nanoscale, this research also opens up exciting possibilities for designing advanced multifunctional catalysts. By leveraging techniques such as electronic structure tuning and heteroatom doping, scientists can now explore a wide array of customized materials optimized for specific applications across the green energy spectrum.

The work by CeNS underscores the potential of interdisciplinary material science in addressing real-world energy challenges. It stands as a shining example of how strategic material design can unlock transformative solutions for a cleaner, more sustainable future.