For decades, chemistry textbooks taught a comforting idea: a catalyst speeds up a reaction and emerges unchanged. On 4 June 2026, the Department of Science & Technology spotlighted Indian research that complicates that picture in a useful way. Dr Neena S. John and research scholar Palash Jyoti Gogoi at the Centre for Nano and Soft Matter Sciences (CeNS), Bengaluru showed that a widely used catalyst actually restructures itself while driving the electrolysis of water to make green hydrogen — and that these live changes strongly shape its performance. Understanding them is a route to cheaper, more efficient hydrogen. For NDA and CDS science sections, it is an ideal hook to nail the basics of electrolysis, catalysts and the hydrogen economy.
The chemistry, in plain language
Electrolysis of water uses electricity to split water (H₂O) into its elements: hydrogen at the cathode and oxygen at the anode. It is a textbook redox (reduction–oxidation) process — reduction at the cathode, oxidation at the anode — the same family of reactions covered in our NDA chemistry notes on redox reactions.
A catalyst is a substance that increases the rate of a reaction without being consumed overall. In electrolysis, the catalysts that coat the electrodes — the electrocatalysts — lower the energy "hill" the reaction must climb (the overpotential), so the same hydrogen is produced using less electricity.
The new insight: the CeNS team found that many such catalysts do not stay structurally fixed during operation. They transform their surface and structure as the reaction proceeds, and these transformations determine how well — and how long — they perform. Designing the next generation of cheap catalysts therefore means designing for this change, not ignoring it.
What makes hydrogen "green" — the colour codes
Hydrogen is colourless; the "colour" describes how it was made, and this is a favourite objective question:
- Green hydrogen — produced by electrolysis powered by renewable electricity (solar, wind). Genuinely low-carbon.
- Grey hydrogen — produced from natural gas (steam methane reforming), emitting CO₂.
- Blue hydrogen — grey hydrogen plus carbon capture and storage, so lower emissions than grey.
- (You may also meet brown/black from coal, and pink from nuclear-powered electrolysis.)
Only green hydrogen is truly clean at production — which is why the whole policy push is about making green hydrogen affordable.
Why the world is betting on hydrogen
Hydrogen is energy-dense and emits only water when used, making it a candidate to decarbonise sectors that are hard to run on batteries alone — steel, fertilisers, refining, long-haul transport and shipping. The catch has always been cost, and a big slice of that cost sits in the electrolyser and its catalysts. Research like the CeNS work attacks the problem at its root: better, cheaper catalysts mean cheaper green hydrogen, which is the difference between a pilot project and an industry.
The static backbone: India's hydrogen push
- National Green Hydrogen Mission: launched in 2023, it aims to make India a global hub for production, use and export of green hydrogen, targeting about 5 Million Metric Tonnes (MMT) of annual production capacity by 2030, with associated renewable capacity and large investment.
- CeNS, Bengaluru: the Centre for Nano and Soft Matter Sciences, an autonomous institute under the DST.
- Climate context: green hydrogen supports India's Net Zero by 2070 pledge and reduces dependence on imported fossil fuels — a recurring energy-security theme.
Why it matters
- Cost reduction: smarter catalysts lower the price of producing green hydrogen.
- Energy security and climate: domestic clean fuel cuts the oil-and-gas import bill and emissions at once.
- Indigenous R&D: an Indian-led discovery feeding directly into a flagship national mission — a point of genuine national capability.
Catalysts beyond hydrogen — the concept generalised
Because "catalyst" is such a high-frequency exam word, it pays to understand it broadly. A catalyst provides an alternative reaction pathway with a lower activation energy, so more reactant molecules can cross the energy barrier per second — speeding the reaction without being used up. Catalysts come in two main types: homogeneous (same phase as the reactants, e.g. dissolved in solution) and heterogeneous (a different phase, e.g. a solid catalyst acting on gases/liquids — like the electrode coatings in an electrolyser, or the catalytic converter in a car). Nature's catalysts are enzymes — biological protein catalysts that run life's chemistry at body temperature. The CeNS finding — that a working catalyst can physically restructure during the reaction — refines the textbook picture: "not consumed overall" does not mean "unchanged at every instant." That nuance is exactly the kind of conceptual upgrade that distinguishes a top answer.
The economics of green hydrogen
The reason catalyst research attracts headlines is money. Producing green hydrogen today is more expensive than making grey hydrogen from natural gas, and the gap is dominated by two factors: the cost of renewable electricity and the cost and efficiency of the electrolyser (where the catalysts live). Many electrolysers rely on scarce, expensive metals such as platinum and iridium; finding cheaper, abundant catalysts that perform as well is therefore a direct route to cheaper hydrogen. Analysts speak of reaching "green hydrogen parity" — the point where green hydrogen costs the same as fossil-based hydrogen — as the trigger for mass adoption. Indian research that lowers catalyst cost or extends catalyst life pushes the country toward that tipping point, and toward the National Green Hydrogen Mission's export ambitions.
Where green hydrogen will actually be used
To make the topic concrete, remember the hard-to-abate sectors green hydrogen targets: steel (replacing coking coal with hydrogen in "green steel"), fertilisers (green ammonia for urea), oil refining, long-haul trucking and shipping (via hydrogen or ammonia fuel), and grid storage (storing surplus solar/wind energy as hydrogen). These are sectors where batteries are impractical because of the sheer energy density or continuous-process requirements. Knowing why hydrogen — not batteries — is the answer for these sectors is the analytical point examiners reward, and it explains why a single catalyst study connects to steel plants, fertiliser security and India's whole decarbonisation strategy.
Rapid revision: lock these in
- What: evidence that catalysts restructure during water electrolysis for green hydrogen.
- Who/where: Dr Neena S. John, CeNS Bengaluru (autonomous institute under DST).
- Electrolysis: splits water → hydrogen + oxygen using electricity (a redox process).
- Catalyst: raises reaction rate without being consumed overall.
- Green vs grey vs blue: renewables-electrolysis vs natural-gas vs gas-plus-carbon-capture.
- National Green Hydrogen Mission: 2023; target ~5 MMT/year by 2030.
Practice questions
Q. "Green hydrogen" is produced by — Electrolysis of water using electricity from renewable sources (solar/wind).
Q. A catalyst is best defined as a substance that — Increases the rate of a reaction without itself being consumed overall.
Q. In the electrolysis of water, hydrogen is liberated at which electrode? The cathode (negative electrode).
Q. Hydrogen made from natural gas without carbon capture is called — Grey hydrogen.
Q. The National Green Hydrogen Mission targets roughly how much annual production by 2030? About 5 Million Metric Tonnes (MMT).
Q. CeNS, which led the catalyst research, works under which department? The Department of Science & Technology (DST).
More quick-fire Q&A
Q. What is "activation energy"? The minimum energy reactant molecules need to react; a catalyst lowers it.
Q. Biological catalysts are called — Enzymes (protein catalysts).
Q. Hydrogen produced by nuclear-powered electrolysis is called — Pink hydrogen.
Q. The device that performs electrolysis of water is an — Electrolyser.
Q. Name two scarce metals often used as electrolysis catalysts. Platinum and iridium.
Q. "Green steel" replaces coking coal with which reductant? Hydrogen.
Q. India's net-zero target year is — 2070.
Q. The institute that led the catalyst study, CeNS, is located in — Bengaluru (under the DST).
Q. The two gases produced in the electrolysis of water are — Hydrogen (at the cathode) and oxygen (at the anode).
Q. "Green hydrogen parity" means — The point where green hydrogen costs the same as fossil-based (grey) hydrogen.
Q. Why are batteries unsuitable for sectors like steel and shipping? Because of the enormous energy density / continuous-process requirements that batteries cannot economically meet — hence hydrogen.
Q. Storing surplus solar or wind energy as hydrogen is a form of — Grid / energy storage.
Q. A car's exhaust device that uses a catalyst to reduce pollutants is the — Catalytic converter.
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One-line takeaway: Indian scientists at CeNS Bengaluru showed that electrolysis catalysts restructure during use — a clue to cheaper green hydrogen, the clean fuel at the heart of India's 2023 National Green Hydrogen Mission and its Net Zero by 2070 goal.