H Li, K Liu, J Fu, K Chen, K Yang, Y Lin, B Yang, Q Wang, H Pan, Z Cai, H Li, M Cao, J Hu, Y-R Lu, T-S Chan, E Cortés, A Fratalocchi, M Liu Paired Ru‒O‒Mo ensemble for efficient and stable alkaline hydrogen evolution reaction Journal Article In: Nano Energy, 82 , pp. 105767, 2021, ISSN: 2211-2855. Abstract | Links @article{,
title = {Paired Ru‒O‒Mo ensemble for efficient and stable alkaline hydrogen evolution reaction},
author = {H Li and K Liu and J Fu and K Chen and K Yang and Y Lin and B Yang and Q Wang and H Pan and Z Cai and H Li and M Cao and J Hu and Y-R Lu and T-S Chan and E Cort\'{e}s and A Fratalocchi and M Liu},
url = {http://www.sciencedirect.com/science/article/pii/S2211285521000252},
doi = {https://doi.org/10.1016/j.nanoen.2021.105767},
issn = {2211-2855},
year = {2021},
date = {2021-04-01},
journal = {Nano Energy},
volume = {82},
pages = {105767},
abstract = {Electrocatalytic hydrogen evolution reaction (HER) in alkaline media is a promising electrochemical energy conversion strategy. Ruthenium (Ru) is an efficient catalyst with a desirable cost for HER, however, the sluggish H2O dissociation process, due to the low H2O adsorption on its surface, currently hampers the performances of this catalyst in alkaline HER. Herein, we demonstrate that the H2O adsorption improves significantly by the construction of Ru\textendashO\textendashMo sites. We prepared Ru/MoO2 catalysts with Ru\textendashO\textendashMo sites through a facile thermal treatment process and assessed the creation of Ru\textendashO\textendashMo interfaces by transmission electron microscope (TEM) and extended X-ray absorption fine structure (EXAFS). By using Fourier-transform infrared spectroscopy (FTIR) and H2O adsorption tests, we proved Ru\textendashO\textendashMo sites have tenfold stronger H2O adsorption ability than that of Ru catalyst. The catalysts with Ru\textendashO\textendashMo sites exhibited a state-of-the-art overpotential of 16 mV at 10 mA cm\textendash2 in 1 M KOH electrolyte, demonstrating a threefold reduction than the previous bests of Ru (59 mV) and commercial Pt (31 mV) catalysts. We proved the stability of these performances over 40 h without decline. These results could open a new path for designing efficient and stable catalysts.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Electrocatalytic hydrogen evolution reaction (HER) in alkaline media is a promising electrochemical energy conversion strategy. Ruthenium (Ru) is an efficient catalyst with a desirable cost for HER, however, the sluggish H2O dissociation process, due to the low H2O adsorption on its surface, currently hampers the performances of this catalyst in alkaline HER. Herein, we demonstrate that the H2O adsorption improves significantly by the construction of Ru–O–Mo sites. We prepared Ru/MoO2 catalysts with Ru–O–Mo sites through a facile thermal treatment process and assessed the creation of Ru–O–Mo interfaces by transmission electron microscope (TEM) and extended X-ray absorption fine structure (EXAFS). By using Fourier-transform infrared spectroscopy (FTIR) and H2O adsorption tests, we proved Ru–O–Mo sites have tenfold stronger H2O adsorption ability than that of Ru catalyst. The catalysts with Ru–O–Mo sites exhibited a state-of-the-art overpotential of 16 mV at 10 mA cm–2 in 1 M KOH electrolyte, demonstrating a threefold reduction than the previous bests of Ru (59 mV) and commercial Pt (31 mV) catalysts. We proved the stability of these performances over 40 h without decline. These results could open a new path for designing efficient and stable catalysts. |
J Kussmann, H Laqua, C Ochsenfeld Highly Efficient Resolution-of-Identity Density Functional Theory Calculations on Central and Graphics Processing Units Journal Article In: Journal of Chemical Theory and Computation, 2021, ISSN: 1549-9618. Abstract | Links @article{,
title = {Highly Efficient Resolution-of-Identity Density Functional Theory Calculations on Central and Graphics Processing Units},
author = {J Kussmann and H Laqua and C Ochsenfeld},
url = {https://doi.org/10.1021/acs.jctc.0c01252},
doi = {10.1021/acs.jctc.0c01252},
issn = {1549-9618},
year = {2021},
date = {2021-02-22},
journal = {Journal of Chemical Theory and Computation},
abstract = {We present an efficient method to evaluate Coulomb potential matrices using the resolution of identity approximation and semilocal exchange-correlation potentials on central (CPU) and graphics processing units (GPU). The new GPU-based RI-algorithm shows a high performance and ensures the favorable scaling with increasing basis set size as the conventional CPU-based method. Furthermore, our method is based on the J-engine algorithm [White; , Head-Gordon, J. Chem. Phys. 1996, 7, 2620], which allows for further optimizations that also provide a significant improvement of the corresponding CPU-based algorithm. Due to the increased performance for the Coulomb evaluation, the calculation of the exchange-correlation potential of density functional theory on CPUs quickly becomes a bottleneck to the overall computational time. Hence, we also present a GPU-based algorithm to evaluate the exchange-correlation terms, which results in an overall high-performance method for density functional calculations. The algorithms to evaluate the potential and nuclear derivative terms are discussed, and their performance on CPUs and GPUs is demonstrated for illustrative calculations.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We present an efficient method to evaluate Coulomb potential matrices using the resolution of identity approximation and semilocal exchange-correlation potentials on central (CPU) and graphics processing units (GPU). The new GPU-based RI-algorithm shows a high performance and ensures the favorable scaling with increasing basis set size as the conventional CPU-based method. Furthermore, our method is based on the J-engine algorithm [White; , Head-Gordon, J. Chem. Phys. 1996, 7, 2620], which allows for further optimizations that also provide a significant improvement of the corresponding CPU-based algorithm. Due to the increased performance for the Coulomb evaluation, the calculation of the exchange-correlation potential of density functional theory on CPUs quickly becomes a bottleneck to the overall computational time. Hence, we also present a GPU-based algorithm to evaluate the exchange-correlation terms, which results in an overall high-performance method for density functional calculations. The algorithms to evaluate the potential and nuclear derivative terms are discussed, and their performance on CPUs and GPUs is demonstrated for illustrative calculations. |
M Peschel, P Kabacinski, D P Schwinger, E Thyrhaug, G Cerullo, T Bach, J Hauer, De R Vivie-Riedle Activation of 2-Cyclohexenone by BF3 Coordination: Mechanistic Insights from Theory and Experiment Journal Article In: Angewandte Chemie International Edition, n/a (n/a), 2021, ISSN: 1433-7851. Abstract | Links @article{,
title = {Activation of 2-Cyclohexenone by BF3 Coordination: Mechanistic Insights from Theory and Experiment},
author = {M Peschel and P Kabacinski and D P Schwinger and E Thyrhaug and G Cerullo and T Bach and J Hauer and De R Vivie-Riedle},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.202016653},
doi = {https://doi.org/10.1002/anie.202016653},
issn = {1433-7851},
year = {2021},
date = {2021-02-17},
journal = {Angewandte Chemie International Edition},
volume = {n/a},
number = {n/a},
abstract = {Lewis acids have recently been recognized as catalysts enabling enantioselective photochemical transformations. Mechanistic studies on these systems are however rare, either due to their absorption at wavelengths shorter than 260 nm, or due to the limitations of theoretical dynamic studies for larger complexes. In this work, we overcome these challenges and employ sub-30-fs transient absorption in the UV, in combination with a highly accurate theoretical treatment on the XMS-CASPT2 level. We investigate 2-cyclohexenone and its complex to boron trifluoride and analyze the observed dynamics based on trajectory calculations including non-adiabatic coupling and intersystem crossing. This approach explains all ultrafast decay pathways observed in the complex. We show that the Lewis acid remains attached to the substrate in the triplet state, which in turn explains why chiral boron-based Lewis acids induce a high enantioselectivity in photocycloaddition reactions.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Lewis acids have recently been recognized as catalysts enabling enantioselective photochemical transformations. Mechanistic studies on these systems are however rare, either due to their absorption at wavelengths shorter than 260 nm, or due to the limitations of theoretical dynamic studies for larger complexes. In this work, we overcome these challenges and employ sub-30-fs transient absorption in the UV, in combination with a highly accurate theoretical treatment on the XMS-CASPT2 level. We investigate 2-cyclohexenone and its complex to boron trifluoride and analyze the observed dynamics based on trajectory calculations including non-adiabatic coupling and intersystem crossing. This approach explains all ultrafast decay pathways observed in the complex. We show that the Lewis acid remains attached to the substrate in the triplet state, which in turn explains why chiral boron-based Lewis acids induce a high enantioselectivity in photocycloaddition reactions. |
