Direct Conversion of N<sub>2</sub> to Nitric Acid via Contact Electrocatalysis
Shaofu Huang, Yuhui Liu, Lincong Ren, Lingyan Huang, Jiahuan Tang, Zhen Yu, Man Chen, Shungui Zhou
Abstract
Nitric acid (HNO 3 ) as a vital chemical is widely used in energy and environmental fields. However, its conventional production relies on ammonia synthesis, resulting in high energy consumption and environmental concerns. Here, we report a simple, efficient, and green conversion of N 2 to HNO 3 by contact electrocatalysis (CEC) under ambient conditions. Utilizing the electrification of poly(tetrafluoroethylene) (PTFE) particles with water under ultrasound, we demonstrate how this interaction promotes the activation of N 2 . Our results showed that the average yield of HNO 3 can reach 40.73 ± 1.80 μM h –1 in air gas atmosphere. We utilized electron spin resonance and the fluorescence spectrum to confirm the evolution of hydroxyl radicals (·OH). High-resolution mass spectrometry combined with isotope experiments provides strong evidence that water-PTFE can produce a contact electric effect through ultrasonic treatment, directly oxidize water or reduce O 2 to produce ·OH, and oxidize N 2 to produce HNO 3 under anaerobic or aerobic conditions. This work not only provides a green and efficient method for direct N 2 fixation into HNO 3 but also stimulates further exploration of CEC-driven chemical processes, particularly highlighting its potential for industrial application, and attempts to explain some of the N 2 fixation phenomena in the environment.