Effect of the Zn(II) on the reduction of Cu(II) in natural clinoptilolite

Iznaga, I. Rodríguez; Petranovskii, Vitalii; Castillón, F. F.; Farı́as, M.H.

doi:10.1016/j.optmat.2006.03.011

Cited by 7 publications

(4 citation statements)

References 11 publications

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“…In polymetallic systems, when compared to monometallic ones, there are considerable differences in the kinds of metal nanospecies obtained by thermal reduction, which, of course, drastically alters the properties of the resulting materials. Thermal reduction in a hydrogen flow for the bimetallic Cu 2+ -Ag + and Cu 2+ -Zn 2+ systems supported on both natural clinoptilolite [18,19,21] and mordenite [20] showed the mutual influence of the Cu 2+ and Ag + cations on the reduction process, and the formation of various nanospecies for both elements. The reduction of Cu 2+ is facilitated by the presence of Ag + and Zn 2+ , mainly at low temperatures.…”

Section: Introductionmentioning

confidence: 95%

“…Important improvements in the properties of nanospecies have been found in multimetallic zeolite-supported materials [17][18][19][20][21]. In polymetallic systems, when compared to monometallic ones, there are considerable differences in the kinds of metal nanospecies obtained by thermal reduction, which, of course, drastically alters the properties of the resulting materials.…”

Section: Introductionmentioning

confidence: 99%

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Mordenite-Supported Ag+-Cu2+-Zn2+ Trimetallic System: A Variety of Nanospecies Obtained via Thermal Reduction in Hydrogen Followed by Cooling in an Air or Hydrogen Atmosphere

et al. 2022

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Multimetallic systems, instead of monometallic systems, have been used to develop materials with diverse supported species to improve their catalytic, antimicrobial activity, etc., properties. The changes in the types of nanospecies obtained through the thermal reduction of ternary Ag+-Cu2+-Zn2+/mordenite systems in hydrogen, followed by their cooling in an air or hydrogen atmosphere, were studied. Such combinations of trimetallic systems with different metal content, variable ratios (between them), and alternating atmosphere types (during the cooling after reducing the samples in hydrogen at 350 °C) lead to diversity in the obtained copper and silver nanospecies. No reduction of Zn2+ was evidenced. A low silver content leads to the formation of reduced silver clusters, while the formation of nanoparticles of a bigger size takes place in the trimetallic samples with high silver content. The cooling of the reduced trimetallic samples in the air causes the oxidation of the obtained metallic clusters and silver and copper nanoparticles. In the case of copper, such conditions lead to the formation of mainly copper (II) oxide, while the silver nanospecies are converted mainly into clusters and nanoparticles. The zinc cations provoked changes in the mordenite matrix, which was associated with the formation of point oxygen defects in the mordenite structure and the formation of surface zinc oxide sub-nanoparticles in the samples cooled in the air.

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Section: Introductionmentioning

confidence: 95%

Section: Introductionmentioning

confidence: 99%

Mordenite-Supported Ag+-Cu2+-Zn2+ Trimetallic System: A Variety of Nanospecies Obtained via Thermal Reduction in Hydrogen Followed by Cooling in an Air or Hydrogen Atmosphere

et al. 2022

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“…In search of the best method, various stabilizers have been used, such as inorganic salts, organic compounds, organic solvents, biological molecules, etc. The influence of the composition of zeolites, that is, their Si/Al ratio, as well as the influence of other exchangeable counter-cations in a binary or ternary mixture of metal cations over zeolite systems have been widely investigated [26][27][28][29][30][31][32][33].…”

Section: Introductionmentioning

confidence: 99%

“…One of the limitations for the use of these materials is the low stability of certain types of copper species [24,44], mainly at low levels of aggregation (nm) and certain states of oxidation (0 and 1+). We paid special attention to the study of copper species deposited on natural and synthetic zeolites in multimetallic systems [4,26,[29][30][31][32]. It has been shown that the addition of a second metal (for example, Zn and Ag) can significantly affect the stabilization of a certain type of copper species and the degree of aggregation of nanoparticles.…”

Section: Introductionmentioning

confidence: 99%

Bimetallic Copper-Silver Systems Supported on Natural Clinoptilolite: Long-Term Changes in Nanospecies Composition and Stability

Rodrı́guez-Iznaga¹,

Petranovskii²,

Chavez-Rivas³

et al. 2022

Preprint

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Long-term changes in nanoparticles of copper-silver bimetallic systems on natural clinoptilolite obtained by ion exchange of Cu2+ and Ag+, and then reduced at different temperatures, have been studied. Even after storage under ambient conditions, XRD and UV-Vis diffuse reflectance spectra indicate the presence of nanospecies of reduced copper and silver. Scanning Electron Microscopy of aged bimetallic samples, reduced at the highest temperature (450oC) and the primary samples for their preparation, also aged, showed the presence of silver nanoparticles with a size of about 100 nm. They are formed in the initial ion-exchanged sample (without reduction) due to the degradation of Ag+ ions. The nanoparticles in the reduced sample are larger; in both samples they are evenly distributed over the surface. The presence of silver affects the stability and the mechanism of decomposition/oxidation of reduced copper nanospecies, and this stability is higher in bimetallic systems. The decomposition pattern of recently reduced species includes the formation of smaller nanoparticles and few-atomic clusters. This can occur, preceding the complete oxidation of Cu to ions. Quasi-colloidal silver, which is present in fresh bimetallic samples reduced at lower temperatures, transforms after aging into Ag8 clusters, which indicates the stability of these nanospecies on natural clinoptilolite.

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A novel approach to prepare Cu(I)Zn@MIL-100(Fe) adsorbent with high CO adsorption capacity, CO/CO2 selectivity and stability via controlled host–guest redox reaction

Lee

Kim

et al. 2021

Chemical Engineering Journal

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Effect of the Zn(II) on the reduction of Cu(II) in natural clinoptilolite

Cited by 7 publications

References 11 publications

Mordenite-Supported Ag+-Cu2+-Zn2+ Trimetallic System: A Variety of Nanospecies Obtained via Thermal Reduction in Hydrogen Followed by Cooling in an Air or Hydrogen Atmosphere

Mordenite-Supported Ag+-Cu2+-Zn2+ Trimetallic System: A Variety of Nanospecies Obtained via Thermal Reduction in Hydrogen Followed by Cooling in an Air or Hydrogen Atmosphere

Bimetallic Copper-Silver Systems Supported on Natural Clinoptilolite: Long-Term Changes in Nanospecies Composition and Stability

A novel approach to prepare Cu(I)Zn@MIL-100(Fe) adsorbent with high CO adsorption capacity, CO/CO2 selectivity and stability via controlled host–guest redox reaction

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