A ‘greener’ way to make fertiliser

A team of international scientists led by NTU Singapore has devised a new ‘greener’ method to make a key compound in fertiliser, and that may pave the way to a more sustainable agricultural practice as global food demand rises.

Devised by NTU researchers, the method produces a compound known as ‘urea’, which is a natural product found in the urine of mammals, and an essential compound for fertilisers that is mass-produced industrially to increase crop yields.

However, the current industrial method used to make urea is a costly, fossil fuel reliant, energy-intensive process that creates significant CO2 emissions, contributing to annual global energy use.
Seeking a more sustainable and energy-efficient method, the team found a way to greatly improve an existing alternative approach to urea production known as electrocatalysis – using electricity to drive chemical reactions in a solution.

Using the nanomaterial indium hydroxide as a catalyst, the researchers reacted nitrate and carbon dioxide and found that the process formed urea five times more efficiently than previously reported attempts using electrocatalysis, specifically by causing the chemical reaction to take place in a ‘highly selective’ manner.

The result is a ‘greener’ method that is not only highly efficient, but it also produces a urea yield that is competitive to the industrial method.