Scientists developed Energy Efficient Hydrogen from urea electrolysis

Electrolysis of urea has helped Indian Scientists produce low-cost hydrogen which will benefit in meeting the energy needs of the country. Mr. Alex C, Mr. Gaurav Shukla, Mr. Muhammed Safeer N. K., and Dr. Neena S John from the Centre for Nano and Soft Matter Sciences (CeNS), an autonomous institute of the Department of Science & Technology, Govt. of India have developed this Nickel oxide (NiOx) based system for producing hydrogen from electro-oxidation of urea. Urea electrolysis is helpful towards urea-based waste treatment with low-cost hydrogen production. This can be utilized for energy production towards our country’s benefits. Indian Scientists have designed an electrocatalyst system for energy-efficient hydrogen production with the help of the electrolysis of urea.

The energy requirement for the production of hydrogen through water electrolysis can be reduced by 70 % through urea electrolysis. The energy-intensive counterpart of water splitting, oxygen evolution, can be replaced with urea oxidation in urea electrolysis. The low-cost, earth-abundant Ni-based catalysts are widely applied for this process. The main challenge associated with urea oxidation is retaining the prolonged activity of the catalyst as the strong adsorption of the reactive intermediate (COx) on the active site, referred to as catalyst poisoning, causes activity loss.

In the series of research works published in the journals ‘Electrochimica Acta’ and ‘Journal of Materials Chemistry A, the scientists have explored electrocatalysts and shown that it is efficient.

They have used high-energy electron beams to produce surface defective unsaturated sites in Nickel Oxide (e-NiO). The study reveals that e-NiO prefers direct mechanisms of urea electro-oxidation due to strong adsorption of urea molecules, whereas NiO favors indirect mechanisms with low activity.

Further, the prominent electrocatalyst poison COx could be removed by adjusting the molar ratio of KOH and Urea with improved kinetics.The urea electrolysis is helpful towards urea-based waste treatment with low-cost hydrogen production.  The researchers, Alex and Gaurav, are of the opinion that the e-beam treatment is an effective way to produce a large number of coordinatively unsaturated active sites on electrocatalysts. It was observed that these generated sites effectively adsorb urea and favors direct urea electro-oxidation mechanisms (UOR). The researcher, Safeer, continued the studies on another Ni3+ oxide system (Ni2O3), revealing that active species Ni3+O(OH) on Ni2O3 possess higher COx tolerance than NiO. The active species of high valent Ni oxide system has a profound effect on catalyst activity.

This race towards green energy assumes significance at a time the ongoing Russia-Ukraine crisis has raised energy costs across the world, hurting in particular India, which imports 85% of its oil and 53% of natural gas requirements.The government will also mandate the use of green hydrogen and green ammonia under the different  policies in a phased manner.

India is one of the top countries by urea production, and it produced 244.55 LMT of urea during 2019-20. The nitrogenous fertilizer industries generate a high concentration of ammonia and urea as effluents. This can be utilized for energy production towards the country’s benefits.