Electrocatalytic nitrogen cycle: mechanism, materials, and momentum

Artificial nitrogen fixation has been pivotal in escalating agricultural productivity and sustaining exponential human population growth. Nonetheless, these practices have concurrently perturbed the natural nitrogen cycle, engendering a plethora of environmental challenges. The advent of electrochemical nitrogen transformation techniques represents a burgeoning avenue for rectifying the nitrogen cycle's imbalance and for synthesizing value-added nitrogenous products from atmospheric nitrogen. In this review, we delve into the recent progress concerning the electrocatalytic interconversion among key nitrogen species, namely N2, NOx(-), and NH3. Our examination encompasses a multifaceted analysis, including the elucidation of reaction mechanisms and a critical evaluation of the intrinsic challenges behind each reaction and the strategies to boost their translation to practical applications. Extending beyond primary nitrogen transformations, we also assess a spectrum of emergent and promising directions. These include lithium-mediated nitrogen fixation, carbon-nitrogen coupling reactions, and the development of electrochemical batteries harnessing nitrogen transformation chemistry. This review aims to offer a critical and forward-looking perspective on the role of electrocatalysis in modulating the nitrogen cycle and to highlight untapped opportunities for its application in a myriad of innovative domains.