Abstract
Two Ru hydride complexes, Cp∗Ru(PPh 2NBn 2)H (1-H) and Cp∗Ru(PtBu 2NBn 2)H (2-H) supported by cyclic PR 2NR' 2 ligands (Cp∗ = η5-C5Me5; PR 2NBn 2 = 1,5-dibenzyl,-3,7-R-1,5-diaza-3,7-diphosphacyclooctane, where R = Ph or tBu) have been developed as electrocatalysts for oxidation of H2 (1.0 atm, 22 °C). The turnover frequency of 2-H is 1.2 s-1 at 22 °C (1.0 atm H2) with an overpotential at Ecat/2 of 0.5 V in the presence of exogenous base, DBU (1,8-diazabicyclo[5.4.0]undec-7-ene), while catalysis by 1-H has a turnover frequency of 0.6 s-1 and an overpotential of 0.6 V at Ecat/2. Addition of H2O facilitates oxidation of H2 by 2-H and increases its turnover frequency to 1.9 s-1, while H2O slows down the catalysis by 1-H. In addition, studies of Cp∗Ru(dmpm)H (where dmpm = bis(dimethylphosphino)methane), a control complex lacking pendent amines in its diphosphine ligand, confirms the critical roles of the pendant amines of the P2N2 ligands as proton relays in the oxidation of H2.
| Original language | English |
|---|---|
| Pages (from-to) | 3630-3639 |
| Number of pages | 10 |
| Journal | Energy and Environmental Science |
| Volume | 7 |
| Issue number | 11 |
| DOIs | |
| Publication status | Published - Nov 1 2014 |
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ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment
- Environmental Chemistry
- Pollution
- Nuclear Energy and Engineering
Cite this
Electrochemical oxidation of H2 catalyzed by ruthenium hydride complexes bearing P2N2 ligands with pendant amines as proton relays. / Liu, Tianbiao; Dubois, Mary Rakowski; DuBois, Daniel L; Bullock, R Morris.
In: Energy and Environmental Science, Vol. 7, No. 11, 01.11.2014, p. 3630-3639.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Electrochemical oxidation of H2 catalyzed by ruthenium hydride complexes bearing P2N2 ligands with pendant amines as proton relays
AU - Liu, Tianbiao
AU - Dubois, Mary Rakowski
AU - DuBois, Daniel L
AU - Bullock, R Morris
PY - 2014/11/1
Y1 - 2014/11/1
N2 - Two Ru hydride complexes, Cp∗Ru(PPh 2NBn 2)H (1-H) and Cp∗Ru(PtBu 2NBn 2)H (2-H) supported by cyclic PR 2NR' 2 ligands (Cp∗ = η5-C5Me5; PR 2NBn 2 = 1,5-dibenzyl,-3,7-R-1,5-diaza-3,7-diphosphacyclooctane, where R = Ph or tBu) have been developed as electrocatalysts for oxidation of H2 (1.0 atm, 22 °C). The turnover frequency of 2-H is 1.2 s-1 at 22 °C (1.0 atm H2) with an overpotential at Ecat/2 of 0.5 V in the presence of exogenous base, DBU (1,8-diazabicyclo[5.4.0]undec-7-ene), while catalysis by 1-H has a turnover frequency of 0.6 s-1 and an overpotential of 0.6 V at Ecat/2. Addition of H2O facilitates oxidation of H2 by 2-H and increases its turnover frequency to 1.9 s-1, while H2O slows down the catalysis by 1-H. In addition, studies of Cp∗Ru(dmpm)H (where dmpm = bis(dimethylphosphino)methane), a control complex lacking pendent amines in its diphosphine ligand, confirms the critical roles of the pendant amines of the P2N2 ligands as proton relays in the oxidation of H2.
AB - Two Ru hydride complexes, Cp∗Ru(PPh 2NBn 2)H (1-H) and Cp∗Ru(PtBu 2NBn 2)H (2-H) supported by cyclic PR 2NR' 2 ligands (Cp∗ = η5-C5Me5; PR 2NBn 2 = 1,5-dibenzyl,-3,7-R-1,5-diaza-3,7-diphosphacyclooctane, where R = Ph or tBu) have been developed as electrocatalysts for oxidation of H2 (1.0 atm, 22 °C). The turnover frequency of 2-H is 1.2 s-1 at 22 °C (1.0 atm H2) with an overpotential at Ecat/2 of 0.5 V in the presence of exogenous base, DBU (1,8-diazabicyclo[5.4.0]undec-7-ene), while catalysis by 1-H has a turnover frequency of 0.6 s-1 and an overpotential of 0.6 V at Ecat/2. Addition of H2O facilitates oxidation of H2 by 2-H and increases its turnover frequency to 1.9 s-1, while H2O slows down the catalysis by 1-H. In addition, studies of Cp∗Ru(dmpm)H (where dmpm = bis(dimethylphosphino)methane), a control complex lacking pendent amines in its diphosphine ligand, confirms the critical roles of the pendant amines of the P2N2 ligands as proton relays in the oxidation of H2.
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U2 - 10.1039/c4ee01262c
DO - 10.1039/c4ee01262c
M3 - Article
VL - 7
SP - 3630
EP - 3639
JO - Energy and Environmental Science
JF - Energy and Environmental Science
SN - 1754-5692
IS - 11
ER -