From UPSC perspective, the following things are important :
Prelims level : Green Hydrogen, Carbon Laser
Mains level : Not Much
Scientists at IIT Mandi have created an innovative carbon-based catalyst that can enhance the efficiency of water electrolysis to generate green hydrogen.
Water electrolysis and its Challenges
- Water electrolysis is the process of splitting water molecules into hydrogen and oxygen using electricity inside an electrolyser.
- However, this process consumes a lot of electrical energy.
- A well-known solution is to use a catalyst to induce the water molecules to split at a much lower energy.
- The better catalysts are often based on the metals iridium and ruthenium, which are expensive, in great demand in other sectors, and not consistently stable as the reaction progresses.
IIT’s breakthrough: Development of Laser Carbon
- Researchers have developed a porous carbon material containing nitrogen that functions both as a catalyst and as the anode in electrolyser units.
- This material, called “laser carbon,” was produced by exposing a sheet of a polymer called polyimide to a laser beam, which carbonised the exposed bits, leaving the remainder rich in nitrogen.
How does laser carbon work?
- The nitrogen atoms in laser carbon draw electron clouds towards themselves, rendering the nearby carbon atoms to bond with atoms or molecules containing electron pairs.
- This makes the location of these atoms active sites for the oxygen evolution reaction (OER).
- OER is a bottleneck in this ideal reaction process because it proceeds slowly, with many intermediate steps, lowering the total reaction efficiency.
- Laser carbon offers to fix this problem by reducing the OER overpotential, which means the reaction kicks off sooner and proceeds with more vigor.
Advantages of laser carbon
Laser carbon has several advantages over other carbon-based catalysts.
- It is “highly power efficient,” cheaper to produce, has a simpler synthesis technique, and “can be batch-manufactured with a laser.”
- The manufacturing process is also environment-friendly, as no waste is generated, and there are no wet chemicals that would require disposal.
- Additionally, it does not require a substrate as it is self-supported in the form of a film, acting as both electrode and electrocatalyst.
- The catalytic activity of laser carbon may not be as high as that of some metals but is comparable.
- Further improvements in the fabrication process and use of other polymers may address this challenge.