TY - JOUR

T1 - Sulfuric Acid Solutions of [Pt(OH)4(H2O)2]: A Platinum Speciation Survey and Hydrated Pt(IV) Oxide Formation for Practical Use

AU - Vasilchenko, Danila

AU - Tkachenko, Pavel

AU - Tkachev, Sergey

AU - Popovetskiy, Pavel

AU - Komarov, Vladislav

AU - Asanova, Tatyana

AU - Asanov, Igor

AU - Filatov, Evgeny

AU - Maximovskiy, Eugene

AU - Gerasimov, Evgeny

AU - Zhurenok, Angelina

AU - Kozlova, Ekaterina

N1 - This work was supported by the Russian Science Foundation (RSF grant 21-73-10038). The authors deeply thank Dr. P.E. Plusnin for his assistance with TGA, Dr. B.A. Kolesov for recording the Raman spectra, and the XRD facility of NIIC SB RAS for the single-crystal data collection. The authors also thank PALII (Pohang, South Korea) for beam allocation time at the 1D-XRS beamline.

PY - 2022/6/27

Y1 - 2022/6/27

N2 - The systematic study of the platinum speciation in sulfuric acid solutions of platinum (IV) hydroxide {[Pt(OH)4(H2O)2], HHPA} was performed with the use of a combination of methods. Depending on the prevailing Pt form, the three regions of H2SO4 concentration were marked: (1) up to 3 M H2SO4 forms unstable solutions gradually generating the PtO2·xH2O particles; (2) 4-12 M H2SO4, where the series of mononuclear aqua-sulfato complexes ([Pt(SO4)n(H2O)6-n]4-2n, where n = 0···4) dominate; and (3) 12 M and above, where, along with [Pt(SO4)n(H2O)6-n]4-2n species, the polynuclear Pt(IV) species and complexes with a bidentate coordination mode of the sulfato ligand are formed. For the first time, the salts of the aqua-hydroxo Pt(IV) cation [Pt(OH)2(H2O)4]SO4 (triclinic and monoclinic phases) were isolated and studied with a combination of methods, including the single-crystal X-ray diffraction. The formation of PtO2·xH2O particles in sulfuric acid solutions (1-3 M) of HHPA and their spectral characteristics and morphology were studied. The deposition of PtO2·xH2O was highlighted as a convenient method to prepare various Pt-containing heterogeneous catalysts. This possibility was illustrated by the preparation of Pt/g-C3N4 catalysts, which show an excellent performance in catalytic H2 generation under visible light irradiation with a quantum efficiency up to 5% and a rate of H2 evolution up to 6.2 mol·h-1 per gram of loaded platinum.

AB - The systematic study of the platinum speciation in sulfuric acid solutions of platinum (IV) hydroxide {[Pt(OH)4(H2O)2], HHPA} was performed with the use of a combination of methods. Depending on the prevailing Pt form, the three regions of H2SO4 concentration were marked: (1) up to 3 M H2SO4 forms unstable solutions gradually generating the PtO2·xH2O particles; (2) 4-12 M H2SO4, where the series of mononuclear aqua-sulfato complexes ([Pt(SO4)n(H2O)6-n]4-2n, where n = 0···4) dominate; and (3) 12 M and above, where, along with [Pt(SO4)n(H2O)6-n]4-2n species, the polynuclear Pt(IV) species and complexes with a bidentate coordination mode of the sulfato ligand are formed. For the first time, the salts of the aqua-hydroxo Pt(IV) cation [Pt(OH)2(H2O)4]SO4 (triclinic and monoclinic phases) were isolated and studied with a combination of methods, including the single-crystal X-ray diffraction. The formation of PtO2·xH2O particles in sulfuric acid solutions (1-3 M) of HHPA and their spectral characteristics and morphology were studied. The deposition of PtO2·xH2O was highlighted as a convenient method to prepare various Pt-containing heterogeneous catalysts. This possibility was illustrated by the preparation of Pt/g-C3N4 catalysts, which show an excellent performance in catalytic H2 generation under visible light irradiation with a quantum efficiency up to 5% and a rate of H2 evolution up to 6.2 mol·h-1 per gram of loaded platinum.

UR - http://www.scopus.com/inward/record.url?scp=85132950056&partnerID=8YFLogxK

U2 - 10.1021/acs.inorgchem.2c01134

DO - 10.1021/acs.inorgchem.2c01134

M3 - Article

C2 - 35700060

AN - SCOPUS:85132950056

VL - 61

SP - 9667

EP - 9684

JO - Inorganic Chemistry

JF - Inorganic Chemistry

SN - 0020-1669

IS - 25

ER -