Abstract
Metal hydrides are key intermediates in catalytic proton reduction and dihydrogen oxidation. There is currently much interest in appending proton relays near the metal centre to accelerate catalysis by proton-coupled electron transfer (PCET). However, the elementary PCET steps and the role of the proton relays are still poorly understood, and direct kinetic studies of these processes are scarce. Here, we report a series of tungsten hydride complexes as proxy catalysts, with covalently attached pyridyl groups as proton acceptors. The rate of their PCET reaction with external oxidants is increased by several orders of magnitude compared to that of the analogous systems with external pyridine on account of facilitated proton transfer. Moreover, the mechanism of the PCET reaction is altered by the appended bases. A unique feature is that the reaction can be tuned to follow three distinct PCET mechanisms—electron-first, proton-first or a concerted reaction—with very different sensitivities to oxidant and base strength. Such knowledge is crucial for rational improvements of solar fuel catalysts.
| Original language | English |
|---|---|
| Pages (from-to) | 881-887 |
| Number of pages | 7 |
| Journal | Nature Chemistry |
| Volume | 10 |
| Issue number | 8 |
| DOIs | |
| Publication status | Published - Aug 1 2018 |
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ASJC Scopus subject areas
- Chemistry(all)
- Chemical Engineering(all)
Cite this
Accelerating proton-coupled electron transfer of metal hydrides in catalyst model reactions. / Liu, Tianfei; Guo, Meiyuan; Orthaber, Andreas; Lomoth, Reiner; Lundberg, Marcus; Ott, Sascha; Hammarström, Leif.
In: Nature Chemistry, Vol. 10, No. 8, 01.08.2018, p. 881-887.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Accelerating proton-coupled electron transfer of metal hydrides in catalyst model reactions
AU - Liu, Tianfei
AU - Guo, Meiyuan
AU - Orthaber, Andreas
AU - Lomoth, Reiner
AU - Lundberg, Marcus
AU - Ott, Sascha
AU - Hammarström, Leif
PY - 2018/8/1
Y1 - 2018/8/1
N2 - Metal hydrides are key intermediates in catalytic proton reduction and dihydrogen oxidation. There is currently much interest in appending proton relays near the metal centre to accelerate catalysis by proton-coupled electron transfer (PCET). However, the elementary PCET steps and the role of the proton relays are still poorly understood, and direct kinetic studies of these processes are scarce. Here, we report a series of tungsten hydride complexes as proxy catalysts, with covalently attached pyridyl groups as proton acceptors. The rate of their PCET reaction with external oxidants is increased by several orders of magnitude compared to that of the analogous systems with external pyridine on account of facilitated proton transfer. Moreover, the mechanism of the PCET reaction is altered by the appended bases. A unique feature is that the reaction can be tuned to follow three distinct PCET mechanisms—electron-first, proton-first or a concerted reaction—with very different sensitivities to oxidant and base strength. Such knowledge is crucial for rational improvements of solar fuel catalysts.
AB - Metal hydrides are key intermediates in catalytic proton reduction and dihydrogen oxidation. There is currently much interest in appending proton relays near the metal centre to accelerate catalysis by proton-coupled electron transfer (PCET). However, the elementary PCET steps and the role of the proton relays are still poorly understood, and direct kinetic studies of these processes are scarce. Here, we report a series of tungsten hydride complexes as proxy catalysts, with covalently attached pyridyl groups as proton acceptors. The rate of their PCET reaction with external oxidants is increased by several orders of magnitude compared to that of the analogous systems with external pyridine on account of facilitated proton transfer. Moreover, the mechanism of the PCET reaction is altered by the appended bases. A unique feature is that the reaction can be tuned to follow three distinct PCET mechanisms—electron-first, proton-first or a concerted reaction—with very different sensitivities to oxidant and base strength. Such knowledge is crucial for rational improvements of solar fuel catalysts.
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U2 - 10.1038/s41557-018-0076-x
DO - 10.1038/s41557-018-0076-x
M3 - Article
VL - 10
SP - 881
EP - 887
JO - Nature Chemistry
JF - Nature Chemistry
SN - 1755-4330
IS - 8
ER -