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He K, Zheng J, Jiao J, Yang Y, Li Q, Qin Y, Song L. First-Principles Calculations of the Effect of γ-Alumina Surface Hydroxyl Structures on the Location and Dechlorination of a Platinum Precursor. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024. [PMID: 39153002 DOI: 10.1021/acs.langmuir.4c01306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/19/2024]
Abstract
The interaction between Pt precursors and alumina support is an important step in synthesizing Pt/Al2O3 catalysts, while an in-depth understanding of the interaction is still lacking. Herein, density functional theory (DFT) calculations were performed to simulate the coordination of H2PtCl6 with different surface hydroxyl groups, revealing the influence of the γ-Al2O3 surface hydroxyl structure on the position of the Pt precursor and the removal of Cl ligands. After drying, the interaction mechanism between [PtCl6]2- and alumina support involves hydrogen bonds and van der Waals forces, which are the main driving forces for the structural transformation from [PtCl6]2- coordinated with the surface hydroxyl group into the PtClx(OH)y species (OH is the γ-Al2O3 surface group). HO-μ1-AlVI and H2O-μ1-AlVI on the (100) surface with electrophilicity facilitate hauling and activating the electron-rich [PtCl6]2-, but the nucleophilic (110) surface has a weaker interaction with [PtCl6]2-. Combining free energy and electronic property analysis, the stable structures on the (100) surface after drying treatment are PtCl4(OH)2 and PtCl3(OH)3, while only PtCl4(OH)2 structures can be formed on the (110) surface. This study can deepen our understanding of the interaction mechanism between Al-hydroxyl groups and Pt precursors, providing a theoretical reference for the precise placement of Pt active phases and the construction of metal-support interfaces.
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Affiliation(s)
- Kai He
- Key Laboratory of Petrochemical Catalytic Science and Technology, Liaoning Province, Liaoning Petrochemical University, Fushun, Liaoning 113001, China
- College of Chemistry and Chemical Engineering, China University of Petroleum (East China), Qingdao, Shandong 266580, China
| | - Jian Zheng
- Sinopec Research Institute of Petroleum Processing Co., Ltd., 18 Xueyuan Road, Beijing 100083, China
| | - Jianhao Jiao
- Key Laboratory of Petrochemical Catalytic Science and Technology, Liaoning Province, Liaoning Petrochemical University, Fushun, Liaoning 113001, China
- College of Chemistry and Chemical Engineering, China University of Petroleum (East China), Qingdao, Shandong 266580, China
| | - Ye Yang
- Key Laboratory of Petrochemical Catalytic Science and Technology, Liaoning Province, Liaoning Petrochemical University, Fushun, Liaoning 113001, China
| | - Qiang Li
- Key Laboratory of Petrochemical Catalytic Science and Technology, Liaoning Province, Liaoning Petrochemical University, Fushun, Liaoning 113001, China
| | - Yucai Qin
- Key Laboratory of Petrochemical Catalytic Science and Technology, Liaoning Province, Liaoning Petrochemical University, Fushun, Liaoning 113001, China
| | - Lijuan Song
- Key Laboratory of Petrochemical Catalytic Science and Technology, Liaoning Province, Liaoning Petrochemical University, Fushun, Liaoning 113001, China
- College of Chemistry and Chemical Engineering, China University of Petroleum (East China), Qingdao, Shandong 266580, China
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Hellier A, Chizallet C, Raybaud P. PtO x Cl y (OH) z (H 2 O) n Complexes under Oxidative and Reductive Conditions: Impact of the Level of Theory on Thermodynamic Stabilities. Chemphyschem 2023; 24:e202200711. [PMID: 36216780 PMCID: PMC10100086 DOI: 10.1002/cphc.202200711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 10/07/2022] [Indexed: 02/03/2023]
Abstract
Platinum-based catalysts with Cl- , OH- , O2- and H2 O ligands, are involved in many industrial processes. Their final chemical properties are impacted by calcination and reduction applied during the preparation and activation steps. We investigate their stability under these reactive conditions with density functional theory (DFT). We benchmark various functionals (PBE-dDsC, optPBE, B3LYP, HSE06, PBE0, TPSS, RTPSS and SCAN) against ACFDT-RPA. PBE-dDsC is well adapted, although hybrid functionals are more accurate for redox reactions. Thermodynamic phase diagrams are determined by computing the chemical potential of the species as a function of temperature and partial pressures of H2 O, HCl, O2 and H2 . The stability and nature of the Pt species are highly sensitive to the activation conditions. Under O2 , high temperatures favour PtO2 while under H2 , platinum is easily reduced to Pt(0). Chlorine modifies the coordination sphere of platinum during calcination by stabilizing PtCl4 and shifts the reduction of platinum to higher temperatures under H2 .
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Affiliation(s)
- Adrien Hellier
- IFP Energies Nouvelles, Rond-point de l'échangeur de Solaize, BP 3-69360, Solaize, France
| | - Céline Chizallet
- IFP Energies Nouvelles, Rond-point de l'échangeur de Solaize, BP 3-69360, Solaize, France
| | - Pascal Raybaud
- IFP Energies Nouvelles, Rond-point de l'échangeur de Solaize, BP 3-69360, Solaize, France.,Univ Lyon, ENS de Lyon, CNRS, Université Claude Bernard Lyon 1, Laboratoire de Chimie UMR 5182, 69342, Lyon, France
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3
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Troncoso FD, Costilla IO, Tonetto GM. Hydrogenation of vegetable oil using highly dispersed Pt/
γ‐Al
2
O
3
catalyst: Effects of key operating parameters and deactivation study. J AM OIL CHEM SOC 2022. [DOI: 10.1002/aocs.12614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Franco David Troncoso
- Departamento de Ingeniería Química Universidad Nacional del Sur (UNS) Bahía Blanca Argentina
- Planta Piloto de Ingeniería Química—PLAPIQUI (UNS‐CONICET) Bahía Blanca Argentina
| | - Ignacio Oscar Costilla
- Planta Piloto de Ingeniería Química—PLAPIQUI (UNS‐CONICET) Bahía Blanca Argentina
- Departamento de Ingeniería Universidad Nacional del Sur (UNS) Bahía Blanca Argentina
| | - Gabriela Marta Tonetto
- Departamento de Ingeniería Química Universidad Nacional del Sur (UNS) Bahía Blanca Argentina
- Planta Piloto de Ingeniería Química—PLAPIQUI (UNS‐CONICET) Bahía Blanca Argentina
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4
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Kriek RJ, Mogwase BM, Vorster SW. Relation of the electrochemical interplay between H
2
PtCl
6
and H
2
O/H
3
O
+
/H
2
+
and the hydrogen‐evolution reaction. ELECTROCHEMICAL SCIENCE ADVANCES 2022. [DOI: 10.1002/elsa.202100041] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Affiliation(s)
- Roelof J. Kriek
- Electrochemistry for Energy & Environment Group Research Focus Area: Chemical Resource Beneficiation (CRB) North‐West University Potchefstroom South Africa
| | - Boitumelo M.S. Mogwase
- Electrochemistry for Energy & Environment Group Research Focus Area: Chemical Resource Beneficiation (CRB) North‐West University Potchefstroom South Africa
| | - Schalk W. Vorster
- Electrochemistry for Energy & Environment Group Research Focus Area: Chemical Resource Beneficiation (CRB) North‐West University Potchefstroom South Africa
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5
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Selective recovery of platinum from spent autocatalyst solution by thiourea modified magnetic biocarbons. Sci Rep 2021; 11:19281. [PMID: 34588491 PMCID: PMC8481563 DOI: 10.1038/s41598-021-98118-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Accepted: 09/03/2021] [Indexed: 11/09/2022] Open
Abstract
The precious platinum group metals distributed in urban industrial products should be recycled because of their rapid decline in the contents through excessive mining. In this work, thiourea modified magnetic biocarbons are prepared via an energy-efficient microwave-assisted activation and assessed as potential adsorbents to recover platinum ions (i.e., Pt(IV)) from dilute waste solution. The physicochemical properties of prepared biocarbons are characterized by a series of spectroscopic and analytic instruments. The adsorption performance of biocarbons is carried out by using batch tests. Consequently, the maximum adsorption capacity of Pt(IV) observed for adsorbents is ca. 42.8 mg g-1 at pH = 2 and 328 K. Both adsorption kinetics and isotherm data of Pt(IV) on the adsorbents are fitted better with non-linear pseudo second-order model and Freundlich isotherm, respectively. Moreover, the thermodynamic parameters suggest that the Pt(IV) adsorption is endothermic and spontaneous. Most importantly, the adsorbents exhibit high selectivity toward Pt(IV) adsorption and preserve ca. 96.9% of adsorption capacity after six cyclic runs. After adsorption, the regeneration of the prepared adsorbents can be effectively attained by using 1 M thiourea/2% HCl mixed solution as an eluent. Combined the data from Fourier transform infrared and X-ray photoelectron spectroscopies, the mechanisms for Pt(IV) adsorption are governed by Pt-S bond between Pt(IV) and thiourea as well as the electrostatic attraction between anionic PtCl62- and cationic functional groups of adsorbents. The superior Pt(IV) recovery and sustainable features allow the thiourea modified magnetic biocarbon as a potential adsorbent to recycle noble metals from spent autocatalyst solution.
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6
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Belskaya OB, Likholobov VA. Development of Approaches to the Formation of Platinum Sites with Desired Properties Using Layer-Structured Supports. RUSS J GEN CHEM+ 2020. [DOI: 10.1134/s1070363220030263] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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7
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Belskaya OB, Duplyakin VK, Likholobov VA. The Role of the Stage of Metal Complex Deposition on Support in the Properties Formation of Supported Platinum Catalysts. KINETICS AND CATALYSIS 2020. [DOI: 10.1134/s0023158419060016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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8
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Belskaya OB, Leont’eva NN, Zaikovskii VI, Kazakov MO, Likholobov VA. Synthesis of layered magnesium-aluminum hydroxide on the γ-Al2O3 surface for modifying the properties of supported platinum catalysts. Catal Today 2019. [DOI: 10.1016/j.cattod.2018.10.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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9
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Tregubenko VY, Udras IE, Gulyaeva TI, Belyi AS. Characteristics and catalytic activity of platinum reforming catalysts based on aluminum oxide modified by organic acids. CATALYSIS IN INDUSTRY 2017. [DOI: 10.1134/s2070050417040110] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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10
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Stepanova LN, Belskaya OB, Likholobov VA. Effect of the nature of the active-component precursor on the properties of Pt/MgAlO
x
catalysts in propane and n-decane dehydrogenation. KINETICS AND CATALYSIS 2017. [DOI: 10.1134/s0023158417040188] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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11
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Yashnik SA, Ishchenko AV, Dovlitova LS, Ismagilov ZR. The Nature of Synergetic Effect of Manganese Oxide and Platinum in Pt–MnOX–Alumina Oxidation Catalysts. Top Catal 2016. [DOI: 10.1007/s11244-016-0722-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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12
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Belskaya OB, Stepanova LN, Gulyaeva TI, Golinskii DV, Belyi AS, Likholobov VA. Study of Pt/MgAlO x catalysts in n-decane dehydrogenation. KINETICS AND CATALYSIS 2015. [DOI: 10.1134/s0023158415050018] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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13
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Belskaya OB, Gulyaeva TI, Talsi VP, Kazakov MO, Nizovskii AI, Kalinkin AV, Bukhtiyarov VI, Likholobov VA. Formation of platinum sites on layered double hydroxide type basic supports: III. Effect of the mechanism of [PtCl6]2− complex binding to aluminum-magnesium layered double hydroxides on the properties of supported platinum in Pt/MgAlO x catalysts. KINETICS AND CATALYSIS 2014. [DOI: 10.1134/s0023158414060020] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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14
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Recovery of Platinum from Spent Reforming Catalyst by Acid Leaching and Coprecipitation. ACTA ACUST UNITED AC 2013. [DOI: 10.1016/j.proeps.2013.01.057] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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15
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Belskaya OB, Mironenko RM, Gulyaeva TI, Duplyakin VK, Likholobov VA. Genesis of the active-component precursor in the synthesis of Pt/Al2O3 catalysts: III. Transformations of adsorbed platinum complexes during drying. KINETICS AND CATALYSIS 2012. [DOI: 10.1134/s0023158412050011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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16
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Dependence of Synergetic Effect of Palladium–Manganese-Hexaaluminate Combustion Catalyst on Nature of Palladium Precursor. Top Catal 2012. [DOI: 10.1007/s11244-012-9874-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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17
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18
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Mondloch JE, Bayram E, Finke RG. A review of the kinetics and mechanisms of formation of supported-nanoparticle heterogeneous catalysts. ACTA ACUST UNITED AC 2012. [DOI: 10.1016/j.molcata.2011.11.011] [Citation(s) in RCA: 111] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
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19
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Mironenko RM, Belskaya OB, Danilova IG, Talsi VP, Likholobov VA. Modifying the functional cover of the γ-Al2O3 surface using organic salts of aluminum. KINETICS AND CATALYSIS 2011. [DOI: 10.1134/s0023158411040094] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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20
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Mondloch JE, Wang Q, Frenkel AI, Finke RG. Development Plus Kinetic and Mechanistic Studies of a Prototype Supported-Nanoparticle Heterogeneous Catalyst Formation System in Contact with Solution: Ir(1,5-COD)Cl/γ-Al2O3 and Its Reduction by H2 to Ir(0)n/γ-Al2O3. J Am Chem Soc 2010; 132:9701-14. [DOI: 10.1021/ja1030062] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Joseph E. Mondloch
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, and Department of Physics, Yeshiva University, New York, New York 10016
| | - Qi Wang
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, and Department of Physics, Yeshiva University, New York, New York 10016
| | - Anatoly I. Frenkel
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, and Department of Physics, Yeshiva University, New York, New York 10016
| | - Richard G. Finke
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, and Department of Physics, Yeshiva University, New York, New York 10016
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21
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Bel’skaya OB, Maevskaya OV, Arbuzov AB, Kireeva TV, Duplyakin VK, Likholobov VA. Effect of the concentration of Pt(IV) and Pd(II) chloro complexes on the proportions of their ion-exchanged and coordinatively bound species on the γ-Al2O3 surface. KINETICS AND CATALYSIS 2010. [DOI: 10.1134/s0023158410010167] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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22
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Espinosa-Alonso L, de Jong KP, Weckhuysen BM. A UV-Vis micro-spectroscopic study to rationalize the influence of Cl−(aq) on the formation of different Pd macro-distributions on γ-Al2O3catalyst bodies. Phys Chem Chem Phys 2010; 12:97-107. [DOI: 10.1039/b915753k] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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23
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Mondloch JE, Yan X, Finke RG. Monitoring Supported-Nanocluster Heterogeneous Catalyst Formation: Product and Kinetic Evidence for a 2-Step, Nucleation and Autocatalytic Growth Mechanism of Pt(0)n Formation from H2PtCl6 on Al2O3 or TiO2. J Am Chem Soc 2009; 131:6389-96. [DOI: 10.1021/ja808980a] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Joseph E. Mondloch
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523
| | - Xinhuan Yan
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523
| | - Richard G. Finke
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523
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24
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Kanda Y, Iwamoto H, Kobayashi T, Uemichi Y, Sugioka M. Preparation of Highly Active Alumina-Pillared Clay Montmorillonite-Supported Platinum Catalyst for Hydrodesulfurization. Top Catal 2009. [DOI: 10.1007/s11244-009-9204-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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25
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Bel’skaya OB, Karymova RK, Kochubey DI, Duplyakin VK. Genesis of the active-component precursor in the synthesis of Pt/Al2O3 catalysts: I. Transformation of the [PtCl6]2− complex in the interaction between chloroplatinic acid and the γ-Al2O3 surface. KINETICS AND CATALYSIS 2008. [DOI: 10.1134/s0023158408050170] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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26
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Belyi AS, Smolikov MD, Kir’yanov DI, Udras IE. Modern views on the state of platinum in supported catalysts for production of motor fuels. RUSS J GEN CHEM+ 2007. [DOI: 10.1134/s1070363207120298] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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27
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Bel’skaya OB, Duplyakin VK. Molecular mechanism of formation of supported platinum catalysts of the Pt/Al2O3 family. RUSS J GEN CHEM+ 2007. [DOI: 10.1134/s1070363207120286] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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28
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Bourikas K, Kordulis C, Lycourghiotis A. The Role of the Liquid‐Solid Interface in the Preparation of Supported Catalysts. CATALYSIS REVIEWS-SCIENCE AND ENGINEERING 2006. [DOI: 10.1080/01614940600962321] [Citation(s) in RCA: 123] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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29
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Abstract
This critical review highlights the progress in (195)Pt NMR over the last 25 years. In particular, some of the recent applications of (195)Pt NMR in catalytic and mechanistic studies, intermetallics and drug binding studies are discussed. (195)Pt NMR chemical shifts obtained from both theoretical studies and experiments are presented for Pt(0), Pt(II), Pt(III) and Pt(IV) complexes. (195)Pt coupling with various nuclei (viz. coupling constants) have also been collected in addition to data on (195)Pt relaxation. The latest developments in the theoretical knowledge and experimental advances have made (195)Pt NMR into a rich source of information in many fields. (164 references.).
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Affiliation(s)
- Brett M Still
- Nanoscale Organisation and Dynamics Group, College of Health and Science, University of Western Sydney, Penrith South DC, NSW 1797, Australia
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30
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Uheida A, Iglesias M, Fontàs C, Hidalgo M, Salvadó V, Zhang Y, Muhammed M. Sorption of palladium(II), rhodium(III), and platinum(IV) on Fe3O4 nanoparticles. J Colloid Interface Sci 2006; 301:402-8. [PMID: 16780854 DOI: 10.1016/j.jcis.2006.05.015] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2006] [Revised: 05/05/2006] [Accepted: 05/09/2006] [Indexed: 10/24/2022]
Abstract
The adsorption of palladium(II), rhodium(III), and platinum(IV) from diluted hydrochloric acid solutions onto Fe(3)O(4) nanoparticles has been investigated. The parameters studied include the contact time and the concentrations of metals and other solutes such as H(+) and chloride. The equilibrium time was reached in less than 20 min for all metals. The maximum loading capacity of Fe(3)O(4) nanoparticles for Pd(II), Rh(III), and Pt(IV) was determined to be 0.103, 0.149, and 0.068 mmol g(-1), respectively. A sorption mechanism for Pd(II), Rh(III), and Pt(IV) has been proposed and their conditional adsorption equilibrium constants have been determined to be logK=1.72, 1.69, and 1.84, respectively. Different compositions of eluting solution were tested for the recovery of Pt(IV), Pd(II), and Rh(III) from Fe(3)O(4) nanoparticles. It was found that 0.5 mol L(-1) HNO(3) can elute all of the metal ions simultaneously, while 1 mol L(-1) NaHSO(3) was an effective eluting solution for Rh(III), and 0.5 mol L(-1) NaClO(4) for Pt(IV). In competitive adsorption, the nanoparticles showed stronger affinity for Rh(III) than for Pd(II) and Pt(IV).
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Affiliation(s)
- Abdusalam Uheida
- Materials Chemistry Division, Royal Institute of Technology, 10044 Stockholm, Sweden.
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31
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Kramer J, Koch KR. 195Pt NMR Study of the Speciation and Preferential Extraction of Pt(IV)−Mixed Halide Complexes by Diethylenetriamine-Modified Silica-Based Anion Exchangers. Inorg Chem 2006; 45:7843-55. [PMID: 16961377 DOI: 10.1021/ic0609655] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A detailed 195Pt NMR study of the distribution of Pt(IV) complex species resulting from the aquation of H2PtCl6, H2PtBr6, and mixtures of H2PtCl6/H2PtBr6 in water/dilute HClO4 has been carried out to obtain an understanding of the speciation in these solutions as relevant to the recovery of Pt(IV) complexes from process solutions. A species distribution plot of the [PtCl6]2-, [PtCl5(H2O)]-, and [PtCl4(H2O)2] shows that in equilibrated, relatively concentrated H2PtCl6 solutions ([Pt]t > 0.12 M), the [PtCl4(H2O)2] species is below the 195Pt NMR detection limit; for [Pt]t concentrations < 0.1 M, the relative concentrations of the [PtCl5(H2O)]- and [PtCl4(H2O)2] species increase significantly, as a result of relatively rapid aquation of the [PtCl6]2- and [PtCl5(H2O)]- complexes under these conditions. From this (195)Pt NMR data the aquation constants of [PtCl6]2- and [PtBr6]2- of log K6 approximately 1.75 +/- 0.05 and log K6 approximately 2.71 +/- 0.15, respectively, have been determined at 30 degrees C. In mixtures of H2PtCl6/H2PtBr6 in water, a number of previously unidentified aquated complexes of the general formula [PtCl(5-n)Br(n)(H2O)]- (n = 0-5) could be identified, including the possible geometrical isomers of these complexes. These 195Pt NMR assignments were confirmed by remarkably systematic, linear relationships between the 195Pt chemical shift increments induced by substitution of Cl- ions by n Br- ions in [PtCl(6-n)Br(n)]2- and [PtCl(5-n)Br(n)(H2O)]- complexes. Preferential extraction of the [PtX6]2- (X = Cl, Br, or a mixture of the two halides) species over their corresponding aquated [PtX5(H2O)]- counterparts by silica-based diethylenetriamine anion exchangers could be demonstrated by means of 195Pt NMR spectroscopy.
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Affiliation(s)
- Jurjen Kramer
- Department of Chemistry and Polymer Science, University of Stellenbosch, Private Bag X1, Matieland, 7602 Stellenbosch, South Africa
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32
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Mohino F, Avila P, Salerno P, Bahamonde A, Mendioroz S. PILC-based monolithic catalysts for the selective catalytic reduction of nitrogen oxides by methane in oxygen excess. Catal Today 2005. [DOI: 10.1016/j.cattod.2005.07.090] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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33
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Bourikas K, Kordulis C, Lycourghiotis A. Differential potentiometric titration: development of a methodology for determining the point of zero charge of metal (hydr)oxides by one titration curve. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2005; 39:4100-8. [PMID: 15984788 DOI: 10.1021/es048139n] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
A new methodology is presented, called differential potentiometric titration (DPT), which allows the determination of the point of zero charge (pzc) of metal (hydr)oxides using only one potentiometric curve. By performing extensive simulations of potentiometric titrations for various model (hydr)oxides, we found that an inflection point in a H+(cons,surf) versus pH potentiometric curve (H+(cons,surf): hydrogen ions consumed on the surface of the (hydr)oxide) and a peak in the corresponding differential curve, dH+(cons,surf)/dpH versus pH, appear at a pH equal to the pzc assumed for a model (hydr)oxide. This distinguishable peak appears at the same position irrespective of the surface ionization and the interfacial model adopted as well as the assumed ionic strength. It was found that the aforementioned peak also appears in the high-resolution differential potentiometric curves experimentally determined for four oxides (SiO2, TiO2, gamma-Al2O3, and MgO) that are widely used in various environmental and other technological applications. The application of DPT to the above-mentioned oxides provided practically the same pzc values as the corresponding ones achieved by using four different techniques as well as the corresponding isoelectric point (iep) values determined by microelectrophoresis. Differences between the pzc and iep values determined using various techniques in the case of MgO were attributed to the increasing dissolution of this oxide as pH decreases and the adsorption of cations (Mg2+, Na+) on the MgO/electrolytic solution interface.
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Affiliation(s)
- Kyriakos Bourikas
- Department of Chemistry, University of Patras, GR-26500 Patras, Greece
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Dawody J, Skoglundh M, Wall S, Fridell E. Role of Pt-precursor on the performance of Pt/BaCO3/Al2O3·NOx storage catalysts. ACTA ACUST UNITED AC 2005. [DOI: 10.1016/j.molcata.2004.09.011] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Capek I. Preparation of metal nanoparticles in water-in-oil (w/o) microemulsions. Adv Colloid Interface Sci 2004; 110:49-74. [PMID: 15142823 DOI: 10.1016/j.cis.2004.02.003] [Citation(s) in RCA: 328] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The use of an inorganic phase in water-in-oil microemulsions has received considerable attention for preparing metal particles. This is a new technique, which allows preparation of ultrafine metal particles within the size range 5 nm<particle diameter<50 nm. This article presents a review of the current literature in the field of particle preparation of several metals such as silver, copper, cadmium, cobalt, nickel, cadmium and gold in the inverse microemulsion systems. The reactant metal salts and reducing agents are mostly soluble in water and therefore the nucleation of metal particles proceeds in the water pools of the microemulsion. The rate of particle nucleation is a function of the percolation degree of microemulsion droplets. Besides a short introduction into some aspects of the microemulsion types and formation, we mainly focus on the kinetics of metallic particle formation. Effects of stabilizer (emulsifier) type and concentration and the type of continuous phase, reducing agent and additive on the particle formation are summarized and evaluated. The influence of several other parameters such as temperature, the incident light, the nature of metal salts and reaction conditions are also reviewed. These results indicate that the nature of the stabilizer emulsifier, the surface activity of additives and the colloidal stability of microemulsion droplets play decisive role on the particle size and distribution during the preparation of metal particles.
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Affiliation(s)
- I Capek
- Polymer Institute, Slovak Academy of Sciences, Dúbravská cesta 9, 842 36 Bratislava, Slovakia.
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The double-layer approach to promotion, electrocatalysis, electrochemical promotion, and metal–support interactions. J Catal 2003. [DOI: 10.1016/s0021-9517(02)00127-6] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Understanding the Influence of the Pretreatment Procedure on Platinum Particle Size and Particle-Size Distribution for SiO2 Impregnated with [Pt2+(NH3)4](NO3−)2: A Combination of HRTEM, Mass Spectrometry, and Quick EXAFS. J Catal 2002. [DOI: 10.1006/jcat.2001.3433] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Ingelsten HH, Bagwe R, Palmqvist A, Skoglundh M, Svanberg C, Holmberg K, Shah DO. Kinetics of the Formation of Nano-Sized Platinum Particles in Water-in-Oil Microemulsions. J Colloid Interface Sci 2001; 241:104-111. [PMID: 11502113 DOI: 10.1006/jcis.2001.7747] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The effect of surfactant type and temperature on the kinetics of the formation of platinum nanoparticles in water-in-oil microemulsions by chemical reduction of PtCl(6)(2-) were examined with time-resolved UV-vis absorption spectroscopy. The surfactants used were poly(ethylene glycol)monododecyl ethers (C(12)E(4), C(12)E(5), C(12)E(6)), sodium bis(2-ethylhexyl)sulphosuccinate (AOT), and mixtures of the alcohol ethoxylates and AOT. The oil domain was n-heptane. The microemulsion droplet size was measured by a dynamic light scattering technique (photon correlation spectroscopy) and the final platinum particle size was determined by transmission electron microscopy. The reaction rate for platinum particle formation was approximately the same in microemulsions based on either of the alcohol ethoxylates but considerably lower for microemulsions based on AOT. In microemulsions based on mixtures of an alcohol ethoxylate and AOT the reaction rate was similar to that obtained when alcohol ethoxylate was the sole surfactant. The reaction was observed to be particularly rapid in microemulsions based on combinations of AOT and C(12)E(5) or C(12)E(6), and the rate was relatively independent of the ratio of the nonionic and anionic surfactants. The reaction was found to be of first order for platinum nanoparticles formed in alcohol ethoxylate-, AOT-C(12)E(5)-, and AOT-C(12)E(6)-based microemulsions, whereas in microemulsions with AOT and AOT-C(12)E(4) the reaction rate seemed to be of higher reaction order. The platinum particles were found to be less than 5 nm in average diameter, which was consistent with the microemulsion droplet size. Copyright 2001 Academic Press.
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Lambert JF, Che M. The molecular approach to supported catalysts synthesis: state of the art and future challenges. ACTA ACUST UNITED AC 2000. [DOI: 10.1016/s1381-1169(00)00318-6] [Citation(s) in RCA: 92] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Regalbuto J, Schrier M, Hao X, Spieker W, Kim J, Miller J, Kropf A. Toward a molecular understanding of noble metal catalyst impregnation. ACTA ACUST UNITED AC 2000. [DOI: 10.1016/s0167-2991(00)80641-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2023]
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