Understanding the Intrinsic Surface Reactivity of Single-Layer and Multilayer PdO(101) on Pd(100)

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Understanding the Intrinsic Surface Reactivity of Single-Layer and Multilayer PdO(101) on Pd(100). / Mehar, Vikram; Kim, Minkyu; Shipilin, Mikhail; Van Den Bossche, Maxime; Gustafson, Johan; Merte, Lindsay R.; Hejral, Uta; Grönbeck, Henrik; Lundgren, Edvin; Asthagiri, Aravind; Weaver, Jason F.

I: ACS Catalysis, Vol. 8, Nr. 9, 07.09.2018, s. 8553-8567.

Forskningsoutput: TidskriftsbidragArtikel i vetenskaplig tidskrift

Harvard

Mehar, V, Kim, M, Shipilin, M, Van Den Bossche, M, Gustafson, J, Merte, LR, Hejral, U, Grönbeck, H, Lundgren, E, Asthagiri, A & Weaver, JF 2018, 'Understanding the Intrinsic Surface Reactivity of Single-Layer and Multilayer PdO(101) on Pd(100)', ACS Catalysis, vol. 8, nr. 9, s. 8553-8567. https://doi.org/10.1021/acscatal.8b02191

APA

Mehar, V., Kim, M., Shipilin, M., Van Den Bossche, M., Gustafson, J., Merte, L. R., ... Weaver, J. F. (2018). Understanding the Intrinsic Surface Reactivity of Single-Layer and Multilayer PdO(101) on Pd(100). ACS Catalysis, 8(9), 8553-8567. https://doi.org/10.1021/acscatal.8b02191

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Mehar, Vikram ; Kim, Minkyu ; Shipilin, Mikhail ; Van Den Bossche, Maxime ; Gustafson, Johan ; Merte, Lindsay R. ; Hejral, Uta ; Grönbeck, Henrik ; Lundgren, Edvin ; Asthagiri, Aravind ; Weaver, Jason F. / Understanding the Intrinsic Surface Reactivity of Single-Layer and Multilayer PdO(101) on Pd(100). I: ACS Catalysis. 2018 ; Vol. 8, Nr. 9. s. 8553-8567.

RIS

TY - JOUR

T1 - Understanding the Intrinsic Surface Reactivity of Single-Layer and Multilayer PdO(101) on Pd(100)

AU - Mehar, Vikram

AU - Kim, Minkyu

AU - Shipilin, Mikhail

AU - Van Den Bossche, Maxime

AU - Gustafson, Johan

AU - Merte, Lindsay R.

AU - Hejral, Uta

AU - Grönbeck, Henrik

AU - Lundgren, Edvin

AU - Asthagiri, Aravind

AU - Weaver, Jason F.

PY - 2018/9/7

Y1 - 2018/9/7

N2 - We investigated the intrinsic reactivity of CO on single-layer and multilayer PdO(101) grown on Pd(100) using temperature-programmed reaction spectroscopy (TPRS) and reflection absorption infrared spectroscopy (RAIRS) experiments, as well as density functional theory (DFT) calculations. We find that CO binds more strongly on multilayer than single-layer PdO(101) (∼119 kJ/mol vs 43 kJ/mol), and that CO oxidizes negligibly on single-layer PdO(101), whereas nearly 90% of a saturated layer of CO oxidizes on multilayer PdO(101) during TPRS experiments. RAIRS further shows that CO molecules adsorb on both bridge-Pdcus and atop-Pdcus sites (coordinatively unsaturated Pd sites) of single-layer PdO(101)/Pd(100), while CO binds exclusively on atop-Pdcus sites of multilayer PdO(101). The DFT calculations reproduce the much stronger binding of CO on multilayer PdO(101), as well as the observed binding site preferences, and reveal that the stronger binding is entirely responsible for the higher CO oxidation activity of multilayer PdO(101)/Pd(100). We show that the O atom below the Pdcus site, present only on multilayer PdO(101), modifies the electronic states of the Pdcus atom in a way that enhances the CO-Pdcus bonding. Lastly, we show that a precursor-mediated kinetic model, with energetics determined from the present study, predicts that the intrinsic CO oxidation rates achieved on both single-layer and multilayer PdO(101)/Pd(100) can be expected to exceed the gaseous CO diffusion rate to the surface during steady-state CO oxidation at elevated pressures, even though the intrinsic reaction rates are 4-5 orders of magnitude lower on single-layer PdO(101)/Pd(100) than on multilayer PdO(101)/Pd(100).

AB - We investigated the intrinsic reactivity of CO on single-layer and multilayer PdO(101) grown on Pd(100) using temperature-programmed reaction spectroscopy (TPRS) and reflection absorption infrared spectroscopy (RAIRS) experiments, as well as density functional theory (DFT) calculations. We find that CO binds more strongly on multilayer than single-layer PdO(101) (∼119 kJ/mol vs 43 kJ/mol), and that CO oxidizes negligibly on single-layer PdO(101), whereas nearly 90% of a saturated layer of CO oxidizes on multilayer PdO(101) during TPRS experiments. RAIRS further shows that CO molecules adsorb on both bridge-Pdcus and atop-Pdcus sites (coordinatively unsaturated Pd sites) of single-layer PdO(101)/Pd(100), while CO binds exclusively on atop-Pdcus sites of multilayer PdO(101). The DFT calculations reproduce the much stronger binding of CO on multilayer PdO(101), as well as the observed binding site preferences, and reveal that the stronger binding is entirely responsible for the higher CO oxidation activity of multilayer PdO(101)/Pd(100). We show that the O atom below the Pdcus site, present only on multilayer PdO(101), modifies the electronic states of the Pdcus atom in a way that enhances the CO-Pdcus bonding. Lastly, we show that a precursor-mediated kinetic model, with energetics determined from the present study, predicts that the intrinsic CO oxidation rates achieved on both single-layer and multilayer PdO(101)/Pd(100) can be expected to exceed the gaseous CO diffusion rate to the surface during steady-state CO oxidation at elevated pressures, even though the intrinsic reaction rates are 4-5 orders of magnitude lower on single-layer PdO(101)/Pd(100) than on multilayer PdO(101)/Pd(100).

KW - CO oxidation

KW - DFT

KW - infrared spectroscopy

KW - palladium

KW - Pd(100)

KW - PdO

KW - RAIRS

KW - surface oxide

U2 - 10.1021/acscatal.8b02191

DO - 10.1021/acscatal.8b02191

M3 - Article

VL - 8

SP - 8553

EP - 8567

JO - ACS Catalysis

T2 - ACS Catalysis

JF - ACS Catalysis

SN - 2155-5435

IS - 9

ER -