Sulfate-Enabled Nitrate Synthesis from Nitrogen Electrooxidation on a Rhodium Electrocatalyst

The electrocatalytic nitrogen oxidation reaction (NOR) to generate nitrate is gaining increasing attention as an alternative approach to the conventional industrial manufacture. But, current progress in NOR is limited by the difficulties in activation and conversion of the strong N equivalent to N bond (941 kJ mol(-1)). Herein, we designed to utilize sulfate to enhance NOR performance over an Rh electrocatalyst. After the addition of sulfate, the inert Rh nanoparticles exhibited superior NOR performance with a nitrate yield of 168.0 mu mol g(cat)(-1) h(-1). The N-15 isotope-labeling experiment confirmed the produced nitrate from nitrogen electrooxidation. A series of electrochemical in situ characterizations and theoretical calculation unveiled that sulfate promoted nitrogen adsorption and decreased the reaction energy barrier, and in situ formed sulfate radicals reduced the activation energy of the potential-determining step, thus accelerating NOR.

Automated summary

The electrocatalytic nitrogen oxidation reaction (NOR) has gained attention as an alternative method for the production of nitrate. By using sulfate, the performance of NOR on a Rh electrocatalyst was enhanced, resulting in a higher nitrate yield. Experimental and theoretical studies revealed that sulfate promoted nitrogen adsorption, decreased reaction energy barriers, and accelerated the NOR process through the formation of sulfate radicals.