Adsorption and dissociation of hydrogen peroxide on small PdxM3-x(M = Pt, Cu; x=1-3) clusters: a hybrid density functional study

作者：Nahali Masoud; Gobal Fereydoon^*; Arab Ramezan

来源：Molecular Physics, 2011, 109(14): 1797-1804.

DOI：10.1080/00268976.2011.592862

• adsorption
• dissociation
• DFT
• hydrogen peroxide
• small cluster

The adsorption and dissociation of H2O2 on small PdxM3-x (M=Pt, Cu; x=1-3) clusters is investigated using the B3PW91 hybrid density functional method. Natural bond orbitals are analysed to obtain partial charges on atoms, dipole moments, bond orders, and hybrid orbitals of the PdxM3-x-H2O2 systems. The calculated adsorption energies are in the range of -0.32 to -2.12 eV. Generally, H2O2 adsorbs on top positions through one of its oxygen atoms and only in a few cases reacts with the cluster through both oxygen and hydrogen sides. In the latter case the cluster sites which are negatively charged interact with the hydrogen atoms. Interestingly, on the triplet Pd2Pt cluster, H2O2 dissociates spontaneously to two OH that adsorb strongly on the Pd sites. In this chemical bond the oxygen p orbitals interact with the Pd d orbitals. Surprisingly, this mode of adsorption never occurs on the singlet Pd2Pt cluster and neither on other clusters with similar charge distributions. We believe that not only the electric field of the positively charged Pd atoms but also the Pd unpaired d electrons in the triplet Pd2Pt cluster make H2O2 dissociative adsorption to be thermodynamically and kinetically favoured.

• 出版日期2011