Efficient catalyst-free N2 fixation by water radical cations under ambient conditions
Xiaoping Zhang, Rui Su, Jingling Li, Liping Huang, Wenwen Yang, Konstantin Chingin, Roman M. Balabin, Jingjing Wang, Xinglei Zhang, Weifeng Zhu, Keke Huang, Shouhua Feng, Huanwen Chen
Abstract
Abstract The growth and sustainable development of humanity is heavily dependent upon molecular nitrogen (N 2 ) fixation. Herein we discover ambient catalyst-free disproportionation of N 2 by water plasma which occurs via the distinctive HONH-HNOH +• intermediate to yield economically valuable nitroxyl (HNO) and hydroxylamine (NH 2 OH) products. Calculations suggest that the reaction is prompted by the coordination of electronically excited N 2 with water dimer radical cation, (H 2 O) 2 +• , in its two-center-three-electron configuration. The reaction products are collected in a 76-needle array discharge reactor with product yields of 1.14 μg cm –2 h –1 for NH 2 OH and 0.37 μg cm –2 h –1 for HNO. Potential applications of these compounds are demonstrated to make ammonia (for NH 2 OH), as well as to chemically react and convert cysteine, and serve as a neuroprotective agent (for HNO). The conversion of N 2 into HNO and NH 2 OH by water plasma could offer great profitability and reduction of polluting emissions, thus giving an entirely look and perspectives to the problem of green N 2 fixation.