TY - JOUR

T1 - Role of surface coverage of alumina with Pt nanoparticles deposited by laser electrodispersion in catalytic CO oxidation

AU - Golubina, E. V.

AU - Rostovshchikova, T. N.

AU - Lokteva, E. S.

AU - Maslakov, K. I.

AU - Nikolaev, S. A.

AU - Shilina, M. I.

AU - Gurevich, S. A.

AU - Kozhevin, V. M.

AU - Yavsin, D. A.

AU - Slavinskaya, E. M.

N1 - The authors acknowledge support from the Lomonosov Moscow State University Program of Development for providing access to the TEM and XPS facilities.

PY - 2021/1/15

Y1 - 2021/1/15

N2 - This work elucidates the role of surface coverage of alumina with Pt nanoparticles on the catalyst efficiency in CO oxidation. Size-selected Pt nanoparticles were deposited on the outer surface of alumina pellets by the laser electrodispersion technique. The alumina surface coverage with Pt varied from 0.04 to 3.5 nanoparticle layers and affected the Pt electronic state and catalyst efficiency. Even in the multilayer coatings nanoplatinum particles remained isolated. The catalysts were tested in CO oxidation at CO/O2 ratios of 0.2, 1 and 2 in the temperature-programmed and pulse reaction modes. At CO/O2 = 0.2 the temperature of 50% CO conversion increased with decreasing the surface coverage with Pt particles. At CO/O2 = 2 the decrease in the surface coverage enhanced the catalyst activity. Pt0 dominates only in multilayer catalysts, however, approximately half of platinum remained non-oxidized even at such a low metal loading as 0.01 wt%. The change in the electronic state of platinum under the thermal treatment in the reaction mixture affected the catalyst efficiency. The oxidation state of Pt depended on the metal loading, reaction temperature, CO/O2 ratio in the reaction mixture, mode of its feeding and surface coverage with Pt nanoparticles that influenced the interparticle and particle – support interactions.

AB - This work elucidates the role of surface coverage of alumina with Pt nanoparticles on the catalyst efficiency in CO oxidation. Size-selected Pt nanoparticles were deposited on the outer surface of alumina pellets by the laser electrodispersion technique. The alumina surface coverage with Pt varied from 0.04 to 3.5 nanoparticle layers and affected the Pt electronic state and catalyst efficiency. Even in the multilayer coatings nanoplatinum particles remained isolated. The catalysts were tested in CO oxidation at CO/O2 ratios of 0.2, 1 and 2 in the temperature-programmed and pulse reaction modes. At CO/O2 = 0.2 the temperature of 50% CO conversion increased with decreasing the surface coverage with Pt particles. At CO/O2 = 2 the decrease in the surface coverage enhanced the catalyst activity. Pt0 dominates only in multilayer catalysts, however, approximately half of platinum remained non-oxidized even at such a low metal loading as 0.01 wt%. The change in the electronic state of platinum under the thermal treatment in the reaction mixture affected the catalyst efficiency. The oxidation state of Pt depended on the metal loading, reaction temperature, CO/O2 ratio in the reaction mixture, mode of its feeding and surface coverage with Pt nanoparticles that influenced the interparticle and particle – support interactions.

KW - Alumina

KW - CO oxidation

KW - Laser electrodispersion

KW - Nanoparticles

KW - Pt catalyst

KW - Surface coverage

KW - THERMAL-STABILITY

KW - WATER-GAS SHIFT

KW - SIZE

KW - LIGHT-OFF

KW - ADSORPTION

KW - AMBIENT-PRESSURE XPS

KW - PT/AL2O3

KW - CARBON-MONOXIDE

KW - SUPPORTED PLATINUM CATALYSTS

KW - CHARGE-STATE

UR - http://www.scopus.com/inward/record.url?scp=85090554747&partnerID=8YFLogxK

U2 - 10.1016/j.apsusc.2020.147656

DO - 10.1016/j.apsusc.2020.147656

M3 - Article

AN - SCOPUS:85090554747

VL - 536

JO - Applied Surface Science

JF - Applied Surface Science

SN - 0169-4332

M1 - 147656

ER -