TY - JOUR

T1 - Formation of Catalytically Active Nanoparticles under Thermolysis of Silver Chloroplatinate(II) and Chloroplatinate(IV)

AU - Filatov, Evgeny

AU - Smirnov, Pavel

AU - Potemkin, Dmitry

AU - Pishchur, Denis

AU - Kryuchkova, Natalya

AU - Plyusnin, Pavel

AU - Korenev, Sergey

N1 - Funding Information: Funding: This research was funded by the Russian Science Foundation, grant number 21-73-20203 (in part of synthesis and catalytic activity investigation of nano-powders), and by the Ministry of Science and Education of the Russian Federation, project № 121031700315-2 (in part of synthesis and thermal properties investigation of silver-platinum complex salts). Publisher Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland.

PY - 2022/2/1

Y1 - 2022/2/1

N2 - The thermal behaviour of Ag2 [PtCl4 ] and Ag2 [PtCl6 ] complex salts in inert and reducing atmospheres has been studied. The thermolysis of compounds in a helium atmosphere is shown to occur in two stages. At the first stage, the complexes decompose in the temperature range of 350–500◦C with the formation of platinum and silver chloride and the release of chlorine gas. At the second stage, silver chloride is sublimated in the temperature range of 700–900◦C, while metallic platinum remains in the solid phase. In contrast to the thermolysis of Ag2 [PtCl6 ], the thermal decomposition of Ag2 [PtCl4 ] at 350◦C is accompanied by significant heat release, which is associated with disproportionation of the initial salt to Ag2 [PtCl6 ], silver chloride, and platinum metal. It is confirmed by DSC measurements, DFT calculations of a suggested reaction, and XRD. The thermolysis of Ag2 [PtCl4 ] and Ag2 [PtCl6 ] compounds is shown to occur in a hydrogen atmosphere in two poorly separable steps. The compounds are decomposed within 170–350◦C, and silver and platinum are reduced to a metallic state, while a metastable single-phase solid solution of Ag0.67Pt0.33 is formed. The catalytic activity of the resulting nanoalloy Ag0.67Pt0.33 is studied in the reaction of CO total (TOX) and preferential (PROX) oxidation. Ag0.67Pt0.33 enhanced Pt nano-powder activity in CO TOX, but was not selective in CO PROX.

AB - The thermal behaviour of Ag2 [PtCl4 ] and Ag2 [PtCl6 ] complex salts in inert and reducing atmospheres has been studied. The thermolysis of compounds in a helium atmosphere is shown to occur in two stages. At the first stage, the complexes decompose in the temperature range of 350–500◦C with the formation of platinum and silver chloride and the release of chlorine gas. At the second stage, silver chloride is sublimated in the temperature range of 700–900◦C, while metallic platinum remains in the solid phase. In contrast to the thermolysis of Ag2 [PtCl6 ], the thermal decomposition of Ag2 [PtCl4 ] at 350◦C is accompanied by significant heat release, which is associated with disproportionation of the initial salt to Ag2 [PtCl6 ], silver chloride, and platinum metal. It is confirmed by DSC measurements, DFT calculations of a suggested reaction, and XRD. The thermolysis of Ag2 [PtCl4 ] and Ag2 [PtCl6 ] compounds is shown to occur in a hydrogen atmosphere in two poorly separable steps. The compounds are decomposed within 170–350◦C, and silver and platinum are reduced to a metallic state, while a metastable single-phase solid solution of Ag0.67Pt0.33 is formed. The catalytic activity of the resulting nanoalloy Ag0.67Pt0.33 is studied in the reaction of CO total (TOX) and preferential (PROX) oxidation. Ag0.67Pt0.33 enhanced Pt nano-powder activity in CO TOX, but was not selective in CO PROX.

KW - CO PROX

KW - Platinum

KW - Silver

KW - Solid solution of metals

KW - Thermolysis

UR - http://www.scopus.com/inward/record.url?scp=85124599183&partnerID=8YFLogxK

U2 - 10.3390/molecules27041173

DO - 10.3390/molecules27041173

M3 - Article

C2 - 35208959

AN - SCOPUS:85124599183

VL - 27

JO - Molecules

JF - Molecules

SN - 1420-3049

IS - 4

M1 - 1173

ER -