H2 splitting on Pt, Ru and Rh nanoparticles supported on sputtered HOPG

Publication: Research - peer-reviewJournal article – Annual report year: 2011

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H2 splitting on Pt, Ru and Rh nanoparticles supported on sputtered HOPG. / Fiordaliso, Elisabetta Maria; Murphy, Shane; Nielsen, R.M.; Dahl, Søren; Chorkendorff, Ib.

In: Surface Science, Vol. 606, No. 3-4, 2012, p. 263-272.

Publication: Research - peer-reviewJournal article – Annual report year: 2011

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Author

Fiordaliso, Elisabetta Maria; Murphy, Shane; Nielsen, R.M.; Dahl, Søren; Chorkendorff, Ib / H2 splitting on Pt, Ru and Rh nanoparticles supported on sputtered HOPG.

In: Surface Science, Vol. 606, No. 3-4, 2012, p. 263-272.

Publication: Research - peer-reviewJournal article – Annual report year: 2011

Bibtex

@article{ca82d9f222c444acb779c83689da4da7,
title = "H2 splitting on Pt, Ru and Rh nanoparticles supported on sputtered HOPG",
keywords = "Nanoparticle, Rhodium, Sticking probability, Platinum, Ruthenium, Desorption energy, Hydrogen, H–D exchange",
publisher = "Elsevier BV North-Holland",
author = "Fiordaliso, {Elisabetta Maria} and Shane Murphy and R.M. Nielsen and Søren Dahl and Ib Chorkendorff",
year = "2012",
doi = "10.1016/j.susc.2011.10.004",
volume = "606",
number = "3-4",
pages = "263--272",
journal = "Surface Science",
issn = "0039-6028",

}

RIS

TY - JOUR

T1 - H2 splitting on Pt, Ru and Rh nanoparticles supported on sputtered HOPG

A1 - Fiordaliso,Elisabetta Maria

A1 - Murphy,Shane

A1 - Nielsen,R.M.

A1 - Dahl,Søren

A1 - Chorkendorff,Ib

AU - Fiordaliso,Elisabetta Maria

AU - Murphy,Shane

AU - Nielsen,R.M.

AU - Dahl,Søren

AU - Chorkendorff,Ib

PB - Elsevier BV North-Holland

PY - 2012

Y1 - 2012

N2 - The equilibrium hydrogen exchange rate between adsorbed and gas phase hydrogen at 1bar is measured for Pt, Ru and Rh nanoparticles supported on a sputtered HOPG substrate. The particles are prepared by Electron Beam Physical Vapor Deposition and the diameter of the particles varies between 2 and 5nm. The rate of hydrogen exchange is measured in the temperature range 40–200°C at 1bar, by utilization of the H–D exchange reaction. We find that the rate of hydrogen exchange increases with the particle diameter for all the metals, and that the rate for Ru and Rh is higher than for Pt. In the case of Pt, the equilibrium dissociative sticking probability, S, is found to be nearly independent of particle diameter. For Ru and Rh, S is found to depend strongly on particle diameter, with the larger particles being more active. The apparent energy of desorption at equilibrium, Eapp, shows a dramatic increase with decreasing particle diameter for diameters below 5nm for Ru and Rh, whereas Eapp is only weakly dependent on particle diameter for Pt. We suggest that the strong variation in the apparent desorption energy with particle diameter for Ru and Rh is due to the formation of compressed hydrogen adlayers on the terraces of the larger particles. Experiments are also carried out in the presence of 10ppm CO. Pt is found to be very sensitive to CO poisoning and the H–D exchange rate drops below the detection limit when CO is added to the gas mixture. In the case of Ru and Rh nanoparticles, CO decreases the splitting rate significantly, also at 200°C. The variation of the sensitivity to CO poisoning with particle diameter for Ru and Rh is found to be weak.

AB - The equilibrium hydrogen exchange rate between adsorbed and gas phase hydrogen at 1bar is measured for Pt, Ru and Rh nanoparticles supported on a sputtered HOPG substrate. The particles are prepared by Electron Beam Physical Vapor Deposition and the diameter of the particles varies between 2 and 5nm. The rate of hydrogen exchange is measured in the temperature range 40–200°C at 1bar, by utilization of the H–D exchange reaction. We find that the rate of hydrogen exchange increases with the particle diameter for all the metals, and that the rate for Ru and Rh is higher than for Pt. In the case of Pt, the equilibrium dissociative sticking probability, S, is found to be nearly independent of particle diameter. For Ru and Rh, S is found to depend strongly on particle diameter, with the larger particles being more active. The apparent energy of desorption at equilibrium, Eapp, shows a dramatic increase with decreasing particle diameter for diameters below 5nm for Ru and Rh, whereas Eapp is only weakly dependent on particle diameter for Pt. We suggest that the strong variation in the apparent desorption energy with particle diameter for Ru and Rh is due to the formation of compressed hydrogen adlayers on the terraces of the larger particles. Experiments are also carried out in the presence of 10ppm CO. Pt is found to be very sensitive to CO poisoning and the H–D exchange rate drops below the detection limit when CO is added to the gas mixture. In the case of Ru and Rh nanoparticles, CO decreases the splitting rate significantly, also at 200°C. The variation of the sensitivity to CO poisoning with particle diameter for Ru and Rh is found to be weak.

KW - Nanoparticle

KW - Rhodium

KW - Sticking probability

KW - Platinum

KW - Ruthenium

KW - Desorption energy

KW - Hydrogen

KW - H–D exchange

U2 - 10.1016/j.susc.2011.10.004

DO - 10.1016/j.susc.2011.10.004

JO - Surface Science

JF - Surface Science

SN - 0039-6028

IS - 3-4

VL - 606

SP - 263

EP - 272

ER -