Understanding plasma-assisted ammonia synthesis via crossing discipline borders of literature: A critical review

Plasma-assisted ammonia (NH 3 ) synthesis is receiving significant attention·NH 3 is globally important to fertilizer production and as a fuel. However, plasma research is, intrinsically, significantly cross-disciplinary and encompasses chemistry, physics , materials science and electrical engineering. A consequence is that it is uncommon for plasma researchers to be fully aware of the entirety of plasma-related research beyond a particular discipline. Here for the first time we critically review this cross-disciplinary literature to address this problem using plasma-enabled NH 3 synthesis as an eminent showcase for process chemistry. A justification is that an improved understanding will be helpful to deal with the complexity of plasma processes which typically involve a set of chemical reactions with an ensemble of many short-lived excited, or reactive, species that vary amongst different plasmas. In this way, mechanisms for plasma-driven NH 3 synthesis are deciphered which helps to improve plasma reaction engineering. Modern analytical techniques are critical in deciphering these fundamentals and in this review optical emission spectroscopy (OES) is featured.