Ultrafine bimetallic Ag-doped Ni nanoparticles embedded in cage-type mesoporous silica SBA-16 as superior catalysts for conversion of toxic nitroaromatic compounds

Budi, Canggih Setya; Deka, Juti Rani; Saikia, Diganta; Kao, Hsien Ming; Yang, Yicheng

doi:10.1016/j.jhazmat.2019.121270

Cited by 35 publications

(38 citation statements)

References 80 publications

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“…To determine the surface composition and the valence state of the Ag nanocatalysts before and after alkali treatment, XPS was carried out (Figure c,d). The Ag 3d spectra of 2.0%Ag@DMSNs and 2.0%Ag–OH – @DMSNs are fitted with two components in accordance with the Ag 0 and Ag + peaks. , The fitting results are summarized in Table S2. We found that with the increase of Ag + contents (Table S2), the reduction rate of catalysts, including 2.0%Ag@DMSNs (Ag + % = ∼7.4%), 2.0%Ag–OH – @DMSNs (Ag + % = ∼63.7%), and 2.0%Ag + @DMSNs (Ag + % = ∼82.8%), first increased from 0.55 to 1.27 min –1 and then decreased to 0.96 min –1 (Figure a).…”

Section: Resultsmentioning

confidence: 99%

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Interfacial Hydroxyl Promotes the Reduction of 4-Nitrophenol by Ag-based Catalysts Confined in Dendritic Mesoporous Silica Nanospheres

Shan

Tao

et al. 2021

J. Phys. Chem. C

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It has been widely accepted that decreasing the pH value could enhance the reactivity of 4-Nitrophenol (4-NP) reduction accompanied with the pillage of H2, but excess hydrogen generation is wasteful and easy to lead to safety problems. Herein, we show that, contrast to previously reported results, interfacial adsorbed hydroxyl significantly promotes reduction of 4-NP using Ag-based nanoparticles (NPs) confined in dendritic mesoporous silica nanospheres (Ag@DMSNs) as a model catalyst at medium concentration of sodium hydroxide (NaOH). We provide strong evidences that adsorptive 4-NP and hydroxyl could spatially interact to form an intermediate state through p-p overlapping of O atoms at nanoscale interface of Ag NPs, which leads to electron redistribution and accelerates N=O bonds cleavage, and consequently accelerates the reduction of 4-NP. The findings of this work demonstrate that improving the catalytic performance can be holistically achieved through manipulating the weak interactions between reactant and enthetic species on the molecule level. Introduction: 4-Aminophenol (4-AP), the reduction product of 4-NP, is a potent intermediate for the manufacture of pharmaceuticals and dyes. 1 However, without the catalyst, the hydrogenation of 4-NP to 4-AP by NaBH4 is kinetically restricted due to kinetic barriers resulting from the large potential difference between 4-NP and BH4-. 2 In recent years, noble metal nanoparticles (MNPs) have been discovered to exhibit high catalytic activity for selective reduction of 4-NP in the presence of NaBH4, such as Ag NPs, 3 Au NPs, 4 Pd NPs, 5 and Pt NPs. 6 Among these MNPs catalysts, Ag-based catalysts are distinctive (easy preparation, relatively low cost, less toxicity, high activity and good stability) and have been extensively utilized for 4-NP reduction. 7 However, it should be noted that MNPs catalysts are susceptible to suffer from aggregating due to the Van der Waals forces and high surface free energy. 8 For 4-NP reduction on Ag-based catalysts, the formation of large metal particles largely affects the catalytic activity and reusable performance. Accordingly, silver nanoparticles anchored through organic (such as polymers and DNA) 9 or inorganic (such as glasses, metal oxides and zeolites) 10 templates have been proposed to address the above issues. Among them, dendritic mesoporous silica nanospheres (DMSNs) composed of cage-like spherical nanopores have been confirmed as a unique confinement matrix for the encapsulation of MNPs and enable their application in catalysis. 11 The catalytic performance of MNPs catalysts strongly depends on their microstructure (catalyst composition, exposed crystal face, defect sits, adsorbed species, etc.) and reaction microenvironment (pressure, solvent, pH etc.). Although the reduction of 4-NP is intensively studied as a model reaction, the reaction mechanism is not yet fully comprehended. It is widely accepted that the reduction of 4-NP follows a multistep reduction process and the 4-hydroxylaminophenol (Hx) is a relative stable inte...

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Section: Resultsmentioning

confidence: 99%

“…The Ag 3d spectra of 2.0%Ag@ DMSNs and 2.0%Ag−OH − @DMSNs are fitted with two components in accordance with the Ag 0 and Ag + peaks. 41,42 The fitting results are summarized in Table S2. We found that with the increase of Ag + contents (Table S2), the reduction rate of catalysts, including 2.0%Ag@DMSNs (Ag + % = ∼7.4%),…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Interfacial Hydroxyl Promotes the Reduction of 4-Nitrophenol by Ag-based Catalysts Confined in Dendritic Mesoporous Silica Nanospheres

Shan

Tao

et al. 2021

J. Phys. Chem. C

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“…Therefore, Ag-Ni@SBA-16C nanocatalysts are considered as promising nanocatalysts for heterogeneous catalysis in reducing nitroaromatic compounds. 58 Also, a novel Pd/m-SBA-15/PDMAEMA catalyst was fabricated by the free radical polymerization of [2-(N,N-dimethylamino) ethyl-methacrylate] (DMAEMA). Pd nanoparticles were incorporated with the polymerized m-SBA-15 to form Pd/m-SBA 15/PDMAEMA novel catalyst (Fig.…”

Section: Silica-based Nanomaterials In Advanced Catalysismentioning

confidence: 99%

“…Therefore, Ag–Ni@SBA–16C nanocatalysts are considered as promising nanocatalysts for heterogeneous catalysis in reducing nitroaromatic compounds. 58…”

Section: Silica-based Nanomaterials and Its Applicationsmentioning

confidence: 99%

Recent progress in the applications of silica-based nanoparticles

Nayl

2022

RSC Adv.

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“…The interest in nanoalloys, or multimetallic nanoparticles, has grown substantially in the recent decades, motivated by the promise of newly emerging materials with unique and tunable properties [1,2]. Among the variety of metals that have been combined into nanoalloys, silver and nickel have been particularly scrutinized, owing to their potential interest in catalysis [3][4][5][6][7][8], energy production [9,10], optics [11] and even as nano inks [12]. As a result, their fundamental properties have been investigated in details as well, in particular their chemical reactivity [13], magnetism [14], or optical and plasmonic response [15][16][17].…”

Section: Introductionmentioning

confidence: 99%

Structural relaxation in Ag-Ni nanoparticles: atomistic modeling away from equilibrium

Calvo

2022

Eur. Phys. J. Appl. Phys.

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The out-of-equilibrium structural relaxation of Ag-Ni nanoparticles containing about 1000--3000 atoms was investigated computationally by means of molecular dynamics trajectories in which the temperature is decreased gradually over hundreds of nanoseconds. At low silver concentration of 10--30\%, the evolution of chemical ordering in Ni$_{\rm core}$Ag$_{\rm shell}$ nanoparticles with different surface arrangements is found to proceed spontaneously and induce some rounding of the nickel core and its partial recristallization. Fast cooling of an initially hot metal vapor mixture was also considered, and it is shown to disfavor silver aggregation at the surface. Silver impurities are also occasionally produced but remain rare events under the conditions of our simulations.

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Ultrafine bimetallic Ag-doped Ni nanoparticles embedded in cage-type mesoporous silica SBA-16 as superior catalysts for conversion of toxic nitroaromatic compounds

Cited by 35 publications

References 80 publications

Interfacial Hydroxyl Promotes the Reduction of 4-Nitrophenol by Ag-based Catalysts Confined in Dendritic Mesoporous Silica Nanospheres

Interfacial Hydroxyl Promotes the Reduction of 4-Nitrophenol by Ag-based Catalysts Confined in Dendritic Mesoporous Silica Nanospheres

Recent progress in the applications of silica-based nanoparticles

Structural relaxation in Ag-Ni nanoparticles: atomistic modeling away from equilibrium

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