NUS develops cadmium iron oxide catalyst to turn CO2 and waste into fertilizer efficiently

Researchers at the National University of Singapore have designed a cadmium-modified iron oxide catalyst that converts carbon dioxide and nitrate into urea fertilizer at industrially relevant rates. The catalyst achieves a urea partial current density of about 140 mA per square centimeter, above the threshold for cost competitive production, and maintains stable operation for 100 hours. The team used AI language models and density functional theory to screen materials and identify the catalyst design. Conventional urea production accounts for over 2 percent of global energy use and emits more than 200 million tonnes of CO2 annually. This electrochemical method uses low carbon electricity instead of fossil fuel based heat, and consumes waste CO2 and nitrate. The cadmium modification suppresses unwanted side reactions like hydrogen gas formation, improving selectivity at high production speeds. The work was published in Nature Synthesis.