Articles written in Journal of Chemical Sciences
Volume 123 Issue 5 September 2011 pp 743-754
An all-electron scalar relativistic calculation on the adsorption of hydrogen molecule onto small copper clusters has been performed by using density functional theory with the generalized gradient approximation (GGA) at PW91 level. Our results reveal that after adsorption of H2 molecule, the Cu-Cu interaction is strengthened and the H-H interaction is weakened, the reactivity enhancement of H2 molecule is obvious. The VIPs, HLGs and VEAs of Cu$_n$H2 clusters show an obvious odd-even oscillation. It is suggested that the H2 molecule is more favourable to be adsorbed by the even-numbered small copper clusters. Meanwhile, the odd-even alteration of magnetic moments is also observed and may be served as the material with tunable code capacity of `0’ and `1' by adsorbing hydrogen molecule onto odd or even-numbered small copper clusters. Some discrepancies of dissociative adsorption between our work and previous works are found and may be understood in terms of the electron pairing effect and the scalar relativistic effect.
Volume 125 Issue 2 March 2013 pp 401-411
A comparative study between all-electron relativistic (AER) calculation and all-electron (AE) calculation on the H2 molecule adsorption onto small gold clusters has been performed. Compared with the corresponding Au$_n$H2 cluster obtained by AE method, the Au$_n$H2 cluster obtained by AER method has much shorter Au-H bond-length, much longer H-H distance, larger binding energy and adsorption energy, higher vertical ionization potentials (VIP), greater charge transfer, higher vibrational frequency of Au-H mode and lower vibrational frequency of H-H mode. The delocalization of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) for Au$_n$H2 cluster obtained by AER method is obvious. All these characteristics suggest that the scalar relativistic effect might strengthen the Au-H bond and weaken the H-H bond. It is believed that the scalar relativistic effect is favourable to the H2 molecule adsorption onto small gold cluster and the reactivity enhancement of H2 molecule. It may be one of the reasons why the dissociative adsorptions take place in some Au$_n$H2 clusters. With increasing size of Au$_n$H2 clusters, the influence of scalar relativistic effect becomes more significant. Some further studies focused on the influence of scalar relativistic effect on the adsorption behaviour of other small molecules onto gold clusters are necessary in the future.
Volume 133, 2021
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