The activation of acetylene by Cu+ ions in zeolites studied by IR spectroscopy

Dátka, Jerzy; Kukulska–Zając, Ewa; Kobyzewa, W.

doi:10.1016/j.cattod.2005.01.009

Cited by 29 publications

(24 citation statements)

References 8 publications

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“…It has been shown that the number and the position of Al atoms in a zeolite framework play a crucial role in determining the type of Cu coordination, inducing different activation and confinement effects, both acting on reactivity 16. These phenomena have been confirmed for acetylene binding to Cu(I)‐zeolites 17. Therefore, we looked for a possible correlation between the different Si/Al ratios of the present Cu‐zeolites and their reactivity.…”

Section: Resultssupporting

confidence: 52%

Zeo‐Click Synthesis: Copper‐Zeolite‐Catalyzed Synthesis of Ynamides

et al. 2014

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Section: Resultssupporting

confidence: 52%

Zeo‐Click Synthesis: Copper‐Zeolite‐Catalyzed Synthesis of Ynamides

et al. 2014

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“…Note that CC stretching vibrational modes of free C 2 H 4 and C 2 H 2 span A g and Σ g + , respectively and thus the modes are IR-inactive [54,55]. Similar symmetry lowering can be seen in the symmetric CH stretching mode in the adsorbed C 2 H 2 , and thus a new IR peak appears around 3273 cm -1 after the C 2 H 2 binding into the monocopper cation [56,57,58]. …”

Section: Resultsmentioning

confidence: 98%

The Variety of Carbon-Metal Bonds inside Cu-ZSM-5 Zeolites: A Density Functional Theory Study

et al. 2010

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Large-scale density functional theory calculations (DFT) found various types of binding of an unsaturated hydrocarbon (C2H2 and C2H4) to a ZSM-5 zeolite extraframework copper cation. We employed the DFT calculations based on the B3LYP functional to obtain local minima of an unsaturated hydrocarbon adsorbed on one or two copper cations embedded inside ZSM-5, and then compared their stabilization energies. The DFT results show that the stabilization energies are strongly dependent on the copper coordination environment as well as configurations of two copper cations. Consequently, the inner copper-carbon bonds are influenced substantially by a nanometer-scale cavity of ZSM-5.

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“…However, the forbidden ν 2 mode could be activated by the adsorption on catalysts surface [53,54]. As shown in Figure 14, the adsorption of acetylene on CuO leads to the appearance of an intense asymmetric ≡ C–H band at 3270 cm −1 (Δν = 17 cm −1 ), which is caused by the interaction between coordinatively unsaturated Cu + cations and the triple bond of acetylene [55,56]. No obvious band for the C≡C bond indicates the symmetrical coordination of acetylene.…”

Section: Discussionmentioning

confidence: 99%

“…For Cu 0.84 Mg 0.16 , the asymmetric ≡ C–H band shifted to 3210 cm −1 (Δν = 77 cm −1 ), indicating the activation ability of C 2 H 2 was further enhanced. This is due to the synergistic interaction of the Cu + species and the nearby medium-strong basic sites [54,55,56,57]. Moreover, the high polarizability of O 2− sites on MgO results in the presence of the should band at 3160 cm −1 (asym.…”

Section: Discussionmentioning

confidence: 99%

Ethynylation of Formaldehyde over Binary Cu-Based Catalysts: Study on Synergistic Effect between Cu+ Species and Acid/Base Sites

et al. 2019

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Most studies on the Cu-based catalysts in the ethynylation of formaldehyde are merely focused on the tuning of electronic configuration and dispersion of the Cu+ species. So far, little attention has been paid to the synergy between Cu species and promoters. Herein, binary nano-CuO-MOx catalysts (M = Si, Al, and Mg) were synthesized and the effects of the promoter on the surface basicity/acidity were systematically studied as well as the ethynylation performance of the nano-CuO-based catalysts. The results show that the introduction of MgO provided a large number of basic sites, which could coordinate with the active Cu+ species and facilitate the dissociation of acetylene as HC ≡ Cδ− and Hδ+. The strongly nucleophilic acetylenic carbon (HC≡Cδ−) is favorable to the attack at the electropositive carbonyl Cδ+ of formaldehyde. The MgO-promoted CuO catalyst showed the highest yield of BD (94%) and the highest stability (the BD yield decreased only from 94% to 82% after eight reaction cycles). SiO2 effectively dispersed Cu species, which improved catalytic activity and stability. However, the introduction of Al2O3 resulted in a large number of acidic sites on the catalyst’s surface. This led to the polymerization of acetylene, which covered the active sites and decreased the catalyst’s activity.

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The activation of acetylene by Cu+ ions in zeolites studied by IR spectroscopy

Cited by 29 publications

References 8 publications

Zeo‐Click Synthesis: Copper‐Zeolite‐Catalyzed Synthesis of Ynamides

Zeo‐Click Synthesis: Copper‐Zeolite‐Catalyzed Synthesis of Ynamides

The Variety of Carbon-Metal Bonds inside Cu-ZSM-5 Zeolites: A Density Functional Theory Study

Ethynylation of Formaldehyde over Binary Cu-Based Catalysts: Study on Synergistic Effect between Cu+ Species and Acid/Base Sites

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