Collaborators at Rice University's George R. Brown School of Engineering, Arizona State University and Pacific Northwest National Laboratory developed the high-performance catalyst that can, with near 100% efficiency, pull ammonia and solid ammonia—akaA study led by Rice chemical and biomolecular engineer Haotian Wang shows the process convertsof 2,000 parts per million into ammonia, followed by an efficient gas stripping process for ammonia product collection.
The researchers knew from previous studies that ruthenium atoms are champs at catalyzing nitrate-rich wastewater. Their twist was combining it with copper that suppresses the hydrogen evolution reaction, a way to produce hydrogen from water that in this case is an unwanted side effect. The team used density functional theory calculations to explain why ruthenium atoms make the chemical path that connects nitrate and ammonia easier to cross, according to co-corresponding author Christopher Muhich, an assistant professor of chemical engineering at Arizona State.
The process works at room temperature and under ambient pressure, and at what the researchers called an"industrial-relevant" nitrate reduction current of 1 amp per square centimeter, the amount of electricity needed to maximize catalysis rate. That should make it easy to scale up, Chen said.