Advancing electrocatalytic nitrogen fixation: insights from molecular systems
Abstract
Nitrogen fixation has a rich history within the inorganic chemistry community. In recent years attention has (re)focused on developing electrocatalytic systems capable of mediating the nitrogen reduction reaction (N₂RR). Well-defined molecular catalyst systems have much to offer in this context. This personal perspective summarizes recent progress from our laboratory at Caltech, pulling together lessons learned from a number of studies we have conducted, placing them within the broader context of thermodynamic efficiency and selectivity for the N₂RR. In particular, proton-coupled electron transfer (PCET) provides an attractive strategy to achieve enhanced efficiency for the multi-electron/proton reduction of N₂ to produce NH₃ (or NH₄⁺), and electrocatalytic PCET (ePCET) via an ePCET mediator affords a promising means of mitigating HER such that the N₂RR can be achieved in a catalytic fashion.
Copyright and License
© The Royal Society of Chemistry 2023.
Acknowledgement
I am indebted to the many talented students and postdocs whose laboratory work, intellectual ideas, and rigorous analyses have shaped the trajectory of our research in N₂R catalysis, including electrocatalysis. A number of coworkers provided critical feedback to drafts of this perspective and deserve special mention. They are Emily Boyd, Dr Pablo Garrido-Barros, Dr Joseph Derosa, Dr Matthew Chalkley, Christian Johansen, and Enric Adillon (who also helped with the TOC graphic). I especially appreciate their catching some errors in thermodynamic values reported. While I alone own any additional thermodynamic fumbles to be found herein, there are fewer as a result of their input. I also thank the NIH (R01 GM-075757) and the DOE (DOE-0235032) for ongoing support of our iron-mediated nitrogen fixation work, and studies of electrocatalytic PCET mediators, respectively. I wish to acknowledge the Resnick Sustainability Institute at Caltech for enabling resources on Caltech's campus that have amplified the research we have been able to carry out.
Additional details
- ISSN
- 1364-5498
- GM-075757
- National Institutes of Health
- DOE-0235032
- United States Department of Energy
- Caltech groups
- Resnick Sustainability Institute