Abstract
A longstanding challenge in molecular electrocatalysis is to design catalysts that break away from the tradeoff between rate and overpotential arising from electronic scaling relationships. Here we report an inversion of the rate-overpotential correlation through system-level design of [Ni(PR 2NR′2)2]2+ electrocatalysts for the production of H2. The overpotential is lowered by an electron-withdrawing ligand, while the turnover frequency is increased by controlling the catalyst structural dynamics, using both ligand design and solvent viscosity. The cumulative effect of controlling each of these system components is an electrocatalyst with a turnover frequency of 70000 s-1 and an overpotential of 230 mV, corresponding to a 100-fold rate enhancement and a 170 mV reduction in overpotential in comparison to the parent nickel catalyst. Molecular Tafel plot analysis reveals that the new catalysts reported here are substantially more efficient than other leading molecular electrocatalysts for the production of H2.
| Original language | English |
|---|---|
| Pages (from-to) | 3286-3296 |
| Number of pages | 11 |
| Journal | ACS Catalysis |
| Volume | 8 |
| Issue number | 4 |
| DOIs | |
| Publication status | Published - Apr 6 2018 |
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Keywords
- Electrocatalysis
- hydrogen
- nickel
- overpotential
- proton relay
- scaling relation
- viscosity
ASJC Scopus subject areas
- Catalysis
Cite this
Reversing the Tradeoff between Rate and Overpotential in Molecular Electrocatalysts for H2 Production. / Klug, Christina M.; Cardenas, Allan Jay P.; Bullock, R Morris; O'Hagan, Molly; Wiedner, Eric.
In: ACS Catalysis, Vol. 8, No. 4, 06.04.2018, p. 3286-3296.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Reversing the Tradeoff between Rate and Overpotential in Molecular Electrocatalysts for H2 Production
AU - Klug, Christina M.
AU - Cardenas, Allan Jay P.
AU - Bullock, R Morris
AU - O'Hagan, Molly
AU - Wiedner, Eric
PY - 2018/4/6
Y1 - 2018/4/6
N2 - A longstanding challenge in molecular electrocatalysis is to design catalysts that break away from the tradeoff between rate and overpotential arising from electronic scaling relationships. Here we report an inversion of the rate-overpotential correlation through system-level design of [Ni(PR 2NR′2)2]2+ electrocatalysts for the production of H2. The overpotential is lowered by an electron-withdrawing ligand, while the turnover frequency is increased by controlling the catalyst structural dynamics, using both ligand design and solvent viscosity. The cumulative effect of controlling each of these system components is an electrocatalyst with a turnover frequency of 70000 s-1 and an overpotential of 230 mV, corresponding to a 100-fold rate enhancement and a 170 mV reduction in overpotential in comparison to the parent nickel catalyst. Molecular Tafel plot analysis reveals that the new catalysts reported here are substantially more efficient than other leading molecular electrocatalysts for the production of H2.
AB - A longstanding challenge in molecular electrocatalysis is to design catalysts that break away from the tradeoff between rate and overpotential arising from electronic scaling relationships. Here we report an inversion of the rate-overpotential correlation through system-level design of [Ni(PR 2NR′2)2]2+ electrocatalysts for the production of H2. The overpotential is lowered by an electron-withdrawing ligand, while the turnover frequency is increased by controlling the catalyst structural dynamics, using both ligand design and solvent viscosity. The cumulative effect of controlling each of these system components is an electrocatalyst with a turnover frequency of 70000 s-1 and an overpotential of 230 mV, corresponding to a 100-fold rate enhancement and a 170 mV reduction in overpotential in comparison to the parent nickel catalyst. Molecular Tafel plot analysis reveals that the new catalysts reported here are substantially more efficient than other leading molecular electrocatalysts for the production of H2.
KW - Electrocatalysis
KW - hydrogen
KW - nickel
KW - overpotential
KW - proton relay
KW - scaling relation
KW - viscosity
UR - http://www.scopus.com/inward/record.url?scp=85045127173&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85045127173&partnerID=8YFLogxK
U2 - 10.1021/acscatal.7b04379
DO - 10.1021/acscatal.7b04379
M3 - Article
VL - 8
SP - 3286
EP - 3296
JO - ACS Catalysis
JF - ACS Catalysis
SN - 2155-5435
IS - 4
ER -