Co-designing Electrocatalytic Systems with Separations To Improve the Sustainability of Reactive Nitrogen Management

Humans have altered the nitrogen cycle to produce nitrogen commodities like fertilizers and chemicals while releasing anthropogenic reactive nitrogen (Nr) contaminants into the environment. These contaminants endanger human and environmental health, but nitrogen commodities are necessary for quality of life. One approach to solving this global challenge is to remove and recover Nr contaminants as commodities; this approach has caught the attention of the electrocatalysis and separations communities alike. In this perspective we propose co-design, or the integration of typically disparate Nr separations and electrocatalytic technologies. We consider real Nr contaminant waste streams and Nr commodity purity requirements. Considering these criteria in electrocatalytic system design reveals fundamental gaps in understanding as well as opportunity for developing co-designed technology that is uniquely tailored to address a challenge in nitrogen management. We focus on three representative challenges in nitrogen management (nitrate, nitrogen oxides, and nitrous oxide), identify their sources and conditions, highlight accomplishments in the fields of electrocatalysis and separations, and explore ways to address each challenge with a co-design approach. We note that this approach will benefit from advancements in related fields such as nitrogen sensing and environmental policy, especially because transformative solutions for the nitrogen challenge lie at the confluence of multiple fields. The final goal is to transition to a circular nitrogen economy that secures a food-safe, environmentally friendly future.