Robust catalyst assessment for the electrocatalytic nitrate reduction reaction

The electrocatalytic nitrate reduction reaction (NO₃RR) can enable distributed conversion of waste to ammonia. Unlike the electrocatalytic dinitrogen reduction reaction, measurements of NO₃RR often consider a fixed quantity of the nitrate anion in a batch system, presenting unique concerns for measurements of catalytic activity and selectivity. In addition, the sensitivity of kinetics and transport to electrolyte composition—where a diverse range of waste feedstocks are of interest—can have a notable impact on catalyst performance, hindering catalyst comparison. We highlight reaction complexities and advocate best practices for robust measurement of catalyst activity, selectivity, and Faradaic efficiency in this burgeoning field.