Investigation of structural and electronic properties of small Au n Cu m (n+m≤5) nano-clusters for Oxygen adsorption

Document Type : Reasearch Paper

Authors

• Razieh Habibpour ¹
• Raheleh Vaziri ²

¹ Department of Chemical Technologies, Iranian Research Organization for Science and Technology, P.O. BOX 3353-5111, Tehran, I. R. Iran.

² Department of Chemistry, Payame Noor University, P.O. BOX 19395-3697, Tehran , I. R. Iran.

10.7508/ijnd.2016.03.004

Abstract

In this study, the structures, the IR spectroscopy, and the electronic properties of AunCum (n+m≤5) bimetallic clusters were studied and compared with those of pure gold and copper clusters using the generalized gradient approximation (GGA) and exchange correlation density functional theory (DFT). The study of an O2-AunCum system is important to identify the promotion effects of each of the two metals and their effect in catalysts, sensors, energy sources, or many other applications. This study also demonstrated that the O2 molecule preferred to adsorb at the Cu site rather than at the Au site in bimetallic clusters. O2 adsorption at a bridge site is energetically more favored over the other sites (1- both oxygen atoms are bonded to the same substrate atom 2- O2 is connected to a Cu atom through a single bond) for oxygen adsorption on these clusters. Further, it was concluded that after the adsorption of the O2 molecule on the bimetallic clusters, the Au-Cu interaction is strengthened and the O-O interaction is weakened; the reactivity improvement of the oxygen molecule was clear.

Keywords

• Bimetallic clusters
• Density functional theory (DMF)
• Density of states
• O2 adsorption
• Vibrational frequency

20.1001.1.20088868.2016.7.3.4.8

Main Subjects

• Nanocatalyst
• Nanochemistry
• Nanoelectronic
• Nanomaterial
• Nanometals

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References

[1] Ekardt W., (1999), Metal Clusters, First ed., USA: Wiley-VCH.

[2] Zhai H. J., Wang L. S., (2005), Chemisorption sites of CO on small gold clusters and transitions from chemisorption to physisorption. J. Chem. Phys. 122: 051101-051111.

[3] Kadossov E., Justin J., Lu M., Rosenmann D., Ocola L. E., Cabrini S., Burghaus U., (2009), Gas–surface interactions with nanocatalysts: Particle size effects in the adsorption dynamics of CO on supported gold clusters. Chem. Phys. Lett. 483: 250-256.

[4] Liu X., Wang A., Wang X., Mou C. Y., Zhang T., (2008), Au–Cu alloy nanoparticles confined in SBA-15 as a highly efficient catalyst for CO oxidation. Chem. Commun. 27: 3187-3191.

[5] Andrews M. P., O’Brien S. C., (1992), Gas‐phase “molecular alloys” of bulk immiscible elements: iron-silver (FexAgy). J. Phys. Chem. 96: 8233-8237.

[6] Lang S. M., Claes P., Cuong N. T., Nguyen M. T., Lievens P., Janssens E., (2011), Copper doping of small gold cluster cations: influence on geometric and electronic structure. J. Chem. Phys. 135: 224305-224311.

[7] Zhao Y. R., Kuang X. Y., Zheng B. B., Li Y. F., Wang S. J., (2011), Equilibrium geometries, stabilities, and electronic properties of the bimetallic M2-doped Aun (M = Ag, Cu; n = 1–10) clusters: comparison with pure gold clusters. J. Phys. Chem. A 115: 569-575.

[8] Kuang X., Wang X., Liu G., (2011), Structural, electronic and magnetic properties of small gold clusters with a copper impurity. Trans. Met. Chem. 36: 643-649.

[9] Wang H. Q., Kuang X. Y., Li H. F., (2010), Density functional study of structural and electronic properties of bimetallic copper-gold clusters: comparison with pure and doped gold clusters. Phys. Chem. Chem. Phys. 12: 5156-5161.

[10] Zorriasatein S., Joshi K., Kanhere D. G., (2008), Electronic and structural investigations of gold clusters doped with copper: Aun-1 Cu- (n=13 – 19). J. Chem. Phys. 128: 184314-7.

[11] Parr R. G., Yang W., (1989), Density-Functional Theory of Atoms and Molecules, New York: Oxford University Press.

[12] Lee C., Yang W., Parr R. G., (1988), Development of the Colle-Salvetti correlation-energy formula into a functional of the electron density. Phys. Rev. B. 37: 785-788.

[13] Wadt W. R., Hay P. J., (1985), Ab initio effective core potentials for molecular calculations. Potentials for the transition metal atoms Sc to Hg. J. Chem. Phys. 82: 270-275.

[14] Zhao Y., Li Z., Yang J., (2009), A density functional study on cationic AunCum+ clusters and their monocarbonyls. Phys. Chem. Chem. Phys. 11: 2329-2335.

[15] Bishea G. A., Pinegar J. C., Morse M. D., (1991), the ground state and excited d‐hole states of CuAu. J. Chem. Phys. 95: 5630-5636.

[16] Frisch M. J., Trucks G. W., Schlegel H. B., Scuseria G. E., Robb M. A., Cheeseman J. R., Montgomery J. A., Vreven T., Kudin K. N., Burant J. C., Millam J. M., Iyengar S. S., Tomasi J., Barone V., Mennucci B., Cossi M., Scalmani G., Rega N., Petersson G. A., Nakatsuji H., Hada M., Ehara M., Toyota K., Fukuda R., Hasegawa J., Ishida M., Nakajima T., Honda Y., Kitao O., Nakai H., Klene M., Li X., Knox J. E., Hratchian H. P., Cross J. B., Bakken V., Adamo C., Jaramillo J., Gomperts R., Stratmann R. E., Yazyev O., Austin A. J., Cammi R., Pomelli C., Ochterski J., Ayala P. Y., Morokuma K., Voth G. A., Salvador. P., Dannenberg J. J., Zakrzewski V. G., Dapprich S., Daniels A. D., Strain M. C., Farkas O., Malick D. K., Rabuck A. D., Raghavachari K., Foresman J. B., Ortiz J. V., Cui Q., Baboul A. G., Clifford S., Cioslowski J., Martin R. L., Fox D. J., Keith T., Al-Laham M. A., Peng C. Y., Nanayakkara A., Challacombe M., Gill P. M. W., Johnson B. G., Chen W., Wong M. W., Gonzalez C., Pople J. A., (2004), Gaussian 03, Revision E.01, Gaussian, Inc., Wallingford: CT.

[17] Zhao S., Lu W. W., Ren Y. L., Wang J. J., Yin W. P., (2012), Density functional study of NOx binding on small AunCum (n + m≤5) clusters. Comp. Theor. Chem. 993: 90-95.

[18] Wang H. Q., Kuang X. Y., Li H. F., (2010), Density functional study of structural and electronic properties of bimetallic copper–gold clusters: comparison with pure and doped gold clusters. Phys. Chem. Chem. Phys. 12: 5156-5159.

[19] Huber K. P., Herzberg G., (1979), Molecular Spectra and Molecular Structure: Constants of Diatomic Molecules, New York: Van Nostrand.

[20] Jackslath C., Rabin I., Schulze W., (1992), Electronic Structures and Related Properties. Electron Impact Ionization Potentials of Gold and Silver Clusters Men; n ≤ 22. Phys. Chem. 96: 1200-1206.

[21] Rohlfing E. A., Valentini J. J., (1986), UV laser excited fluorescence spectroscopy of the jet‐cooled copper dimer. J. Chem. Phys. 84: 6560-6567.

[22] Kuang X., Wang X., Liu G., (2011), Structural, electronic and magnetic properties of small gold clusters with a copper impurity. Trans. Met. Chem. 36: 643-648.

[23] Zhao Y. R., Kuang X. Y., Zheng B. B., Li Y. F., Wang S. J., (2011), Equilibrium geometries, stabilities, and electronic properties of the bimetallic M2-doped Aun (M = Ag, Cu; n = 1–10) clusters: comparison with pure gold clusters. J. Phys. Chem. A. 115: 569-575.

[24] Zhao Y., Li Z., Yang J., (2009), A density functional study on cationic AunCum clusters and their monocarbonyls. Phys. Chem. Chem. Phys. 11: 2329-2336.

[25] Wang H. Q., Kuang X. Y., Li H. F., (2010), Density functional study of structural and electronic properties of bimetallic copper-gold clusters: comparison with pure and doped gold clusters. Phys. Chem. Chem. Phys. 12: 5156-5161.

[26] Zhan C. G., Nichols J. A., Dixon, D. A., (2003), Ionization Potential, Electron Affinity, Electronegativity, Hardness, and Electron Excitation Energy:  Molecular Properties from Density Functional Theory Orbital Energies.  J. Phys. Chem. A. 107: 4184-4189.

[27] Pearson R. G., (1997), Chemical Hardness: Applications from Molecules to Solids, Weinheim: Wiley-VCH.

[28] Greenwood N. N., Earnshaw A., (1984), Chemistry of Elements, Oxford: Pergamon Press.

[29] Huber K. P., Herzberg G., (1979), Molecular Spectra and Molecular Structure: Constants of Diatomic Molecules, New York: Van Nostrand Reinhold.

[30] Parr R. G., Pearson R. G., (1983), Absolute hardness: companion parameter to absolute electronegativity. J. Am. Chem. Soc. 105: 7512-7516.