A Greener Way to Make Fertiliser

Opportunity

This invention offers a novel process for developing a catalyst to form urea, a critical nitrogen fertiliser. Urea, a colourless solid, is the most popular form of nitrogen fertiliser, with global annual production estimated at 200 million tons, valued at $70 billion. Traditionally, urea is produced via the Haber-Bosch/Bosch-Meiser process, a thermocatalytic method requiring high temperatures and pressures. This invention produces urea at around 473K (~200 degC) and 143kPa, significantly reducing the carbon footprint associated with its production. By directly coupling nitrate (NO₃₋) with carbon dioxide (CO₂) on an indium hydroxide catalyst, this power-to-urea approach achieves highly selective urea electrosynthesis under ambient conditions.

Technology

This strategy represents a greener way to produce fertiliser. It involves a method of forming urea using an electrocatalyst and a novel mechanism for its formation. The process demonstrates excellent performance in urea synthesis, achieving high yields, faradaic efficiency and N/C urea-selectivity. It involves a novel mechanism that captures surface electrons via CO₂, transforming semiconductor behaviour and suppressing HER. Further, the preferential coupling of *CO₂ with *NO₂ at an early stage ensures high selectivity in C-N bond formation.

Figure 1: Process for developing a catalyst to form urea.

Applications & Advantages

Applications:

Sustainable Agriculture - Greener fertilisers support sustainable agriculture initiatives by minimising the ecological footprint of farming operations.

Aquaculture - These fertilisers promotes healthy aquatic plant growth and nutrient cycling in aquaculture systems.

Advantages:

• Minimises nutrient runoff and leaching, reducing water pollution and ecosystem degradation.
• Releases nutrients gradually, matching plant uptake patterns and reducing nutrient wastage.
• Reduces greenhouse gases emissions like nitrous oxide, a potent contributor to climate change.
• Enhances soil health by promoting beneficial microbial activity and increasing organic matter content.
• Contains fewer synthetic chemicals and residues, leading to healthier and safer food production.
• Supports soil structure and nutrient balance, preventing soil degradation and erosion.
• Biodegradable and breaks down naturally, reducing long-term environmental impacts.
• Supports biodiversity by reducing nutrient imbalances that favour certain plant species over others.