Author ORCID Identifier
Document Type
Article
Publication Date
1-11-2019
Abstract
There is a growing need for scalable ammonia synthesis at ambient conditions that relies on renewable sources of energy and feedstocks to replace the Haber-Bosch process. Electrically driven approaches are an ideal strategy for the reduction of nitrogen to ammonia but, to date, have suffered from low selectivity associated with the catalyst. Here, we present a hybrid electrolytic system characterized by a gaseous plasma electrode that facilitates the study of ammonia formation in the absence of any material surface. We find record-high faradaic efficiency (up to 100%) for ammonia from nitrogen and water at atmospheric pressure and temperature with this system. Ammonia measurements under varying reaction conditions in combination with scavengers reveal that the unprecedented selectivity is achieved by solvated electrons produced at the plasma-water interface, which react favorably with protons to produce the key hydrogen radical intermediate. Our results demonstrate that limitations in selectivity can be circumvented by using catalyst-free solvated electron chemistry. In the absence of adsorption steps, the importance of controlling proton concentration and transport is also revealed.
Publication Title
Science Advances
Volume
5
Issue
1
Grant
W911NF-17-1-0119; DE-SC0016529
Funder
U.S. Army Research Office; CWRU Faculty Investment Fund; U.S. Department of Energy, Office of Science, Basic Energy Sciences, Catalysis Science Program
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License
Recommended Citation
Hawtof, Ryan; Ghosh, Souvik; Guarr, Evan; Xu, Cheyan; Sankaran, R. Mohan; and Renner, Julie N., "Catalyst-Free, Highly Selective Synthesis of Ammonia from Nitrogen and Water by a Plasma Electrolytic System" (2019). Faculty Scholarship. 17.
https://commons.case.edu/facultyworks/17