TY - JOUR

T1 - Pt/CeO 2 and Pt/CeSnO x catalysts for low-temperature CO oxidation prepared by plasma-arc technique

AU - Kardash, Tatyana Y.

AU - Derevyannikova, Elizaveta A.

AU - Slavinskaya, Elena M.

AU - Stadnichenko, Andrey I.

AU - Maltsev, Vasiliy A.

AU - Zaikovskii, Alexey V.

AU - Novopashin, Sergey A.

AU - Boronin, Andrei I.

AU - Neyman, Konstantin M.

PY - 2019/3/12

Y1 - 2019/3/12

N2 - We applied a method of plasma arc synthesis to study effects of modification of the fluorite phase of ceria by tin ions. By sputtering active components (Pt, Ce, Sn) together with carbon from a graphite electrode in a helium ambient we prepared samples of complex highly defective composite PtCeC and PtCeSnC oxide particles stabilized in a matrix of carbon. Subsequent high-temperature annealing of the samples in oxygen removes the carbon matrix and causes the formation of active catalysts Pt/CeO x and Pt/CeSnO x for CO oxidation. In the presence of Sn, X-Ray Diffraction (XRD) and High-Resolution Transmission Electron Microscopy (HRTEM) show formation of a mixed phase CeSnO x and stabilization of more dispersed species with a fluorite-type structure. These factors are essential for the observed high activity and thermic stability of the catalyst modified by Sn. X-Ray Photoelectron Spectroscopy (XPS) reveals the presence of both Pt 2+ and Pt 4+ ions in the catalyst Pt/CeO x , whereas only the state Pt2+ of platinum could be detected in the Sn-modified catalyst Pt/CeSnO x . Insertion of Sn ions into the Pt/CeO x lattice destabilizes/reduces Pt 4+ cations in the Pt/CeSnO x catalyst and induces formation of strikingly high concentration (up to 50% at.) of lattice Ce 3+ ions. Our DFT calculations corroborate destabilization of Pt 4+ ions by incorporation of cationic Sn in Pt/CeO x . The presented results show that modification of the fluorite lattice of ceria by tin induces substantial amount of mobile reactive oxygen partly due to affecting geometric parameters of ceria by tin ions.

AB - We applied a method of plasma arc synthesis to study effects of modification of the fluorite phase of ceria by tin ions. By sputtering active components (Pt, Ce, Sn) together with carbon from a graphite electrode in a helium ambient we prepared samples of complex highly defective composite PtCeC and PtCeSnC oxide particles stabilized in a matrix of carbon. Subsequent high-temperature annealing of the samples in oxygen removes the carbon matrix and causes the formation of active catalysts Pt/CeO x and Pt/CeSnO x for CO oxidation. In the presence of Sn, X-Ray Diffraction (XRD) and High-Resolution Transmission Electron Microscopy (HRTEM) show formation of a mixed phase CeSnO x and stabilization of more dispersed species with a fluorite-type structure. These factors are essential for the observed high activity and thermic stability of the catalyst modified by Sn. X-Ray Photoelectron Spectroscopy (XPS) reveals the presence of both Pt 2+ and Pt 4+ ions in the catalyst Pt/CeO x , whereas only the state Pt2+ of platinum could be detected in the Sn-modified catalyst Pt/CeSnO x . Insertion of Sn ions into the Pt/CeO x lattice destabilizes/reduces Pt 4+ cations in the Pt/CeSnO x catalyst and induces formation of strikingly high concentration (up to 50% at.) of lattice Ce 3+ ions. Our DFT calculations corroborate destabilization of Pt 4+ ions by incorporation of cationic Sn in Pt/CeO x . The presented results show that modification of the fluorite lattice of ceria by tin induces substantial amount of mobile reactive oxygen partly due to affecting geometric parameters of ceria by tin ions.

KW - Ceria

KW - CO oxidation

KW - DFT calculations

KW - Plasma arc synthesis

KW - Platinum

KW - Pt/CeO catalyst

KW - Tin

KW - THERMAL-STABILITY

KW - COMBUSTION

KW - PLATINUM

KW - Pt/CeO2 catalyst

KW - ceria

KW - LASER-ABLATED NANOPARTICLES

KW - platinum

KW - PD/CEO2 CATALYSTS

KW - SOLID-SOLUTION

KW - CERIA

KW - tin

KW - REDOX

KW - plasma arc synthesis

KW - CEO2

KW - PHOTOELECTRON-SPECTROSCOPY

UR - http://www.scopus.com/inward/record.url?scp=85064616810&partnerID=8YFLogxK

U2 - 10.3389/fchem.2019.00114

DO - 10.3389/fchem.2019.00114

M3 - Article

C2 - 30931295

AN - SCOPUS:85064616810

VL - 7

SP - 114

JO - Frontiers in Chemistry

JF - Frontiers in Chemistry

SN - 2296-2646

IS - MAR

M1 - 114

ER -