Organosiloxane tunability in mesoporous organosilica and punctuated Pd nanoparticles growth; theory and experiment

Doustkhah, Esmail; Mohtasham, Hamed; Farajzadeh, Mustafa; Rostamnia, Sadegh; Wang, Yuan; Arandiyan, Hamidreza; Assadi, M. Hussein N.

doi:10.1016/j.micromeso.2019.109832

Cited by 62 publications

(20 citation statements)

References 37 publications

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“…If higher temperatures accelerate the dehydrogenation reaction in the first hours, as demonstrated by the increasing TOF values presented in Table 2, there is no tremendous effect of the reaction temperature on the final FA conversion values. A similar influence of the reaction temperature on the FA dehydrogenation efficiency in the absence of additives was reported for Ag 74 Pd 26 /graphene [17], Pd/C synthesized in situ with citric acid [3], and Pd@MO-urea [34]. In these cases, an increase of the reaction temperature did not lead to higher final gas volumes, but significantly enhanced the gas generation rate.…”

Section: Influence Of Temperaturesupporting

confidence: 71%

Controllable H2 Generation by Formic Acid Decomposition on a Novel Pd/Templated Carbon Catalyst

et al. 2020

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A novel Pd/templated carbon catalyst (Pd/TC) was developed, characterized, and tested in the dehydrogenation of formic acid (FA) under mild conditions, with the possibility to control the H2 generation rate, in the absence or presence of HCOONa (SF), by adjusting the Pd:FA and/or FA:SF ratios. The characterization results of the templated carbon obtained by the chemical vapor deposition of acetylene on NaY zeolite revealed different structural and morphological properties compared to other C-based supports. Therefore, it was expected to induce a different catalytic behavior for the Pd/TC catalyst. Indeed, the TC-supported Pd catalyst exhibited superior activity in the decomposition of FA, even at room temperature, with turnover frequencies (TOFs) of up to 143.7 and 218.8 h−1 at 60 °C. The H2 generation rate increased with an increasing temperature, while the H2 yield increased with a decreasing FA concentration. Constant generation of gaseous flow (H2 + CO2) was achieved for 11 days, by the complete dehydrogenation of FA at room temperature using a 2 M FA solution and Pd:FA = 1:2100. The presence of SF in the reaction medium significantly enhanced the H2 generation rate (535 h−1 for FA:SF = 3:1 and 60 °C).

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Section: Influence Of Temperaturesupporting

confidence: 71%

Controllable H2 Generation by Formic Acid Decomposition on a Novel Pd/Templated Carbon Catalyst

et al. 2020

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“…In the recent decade, periodic mesoporous organosilica (PMO) materials with an ordered porous structure and wide variety of organic moiety, tunable architecture, and high surface area have been widely employed in the heterogeneous and green design of the catalysts [19,[32][33][34][35][36][37]. Some of them might be promising candidates to generate and support sub-2 nm sized MNPs with uniform distribution, which is the key to attaining high catalytic performance [38][39][40][41]. We studied the tenability of organosiloxane precursors with TEOS in the rational synthesis of PMOs [41].…”

Section: Introductionmentioning

confidence: 99%

“…Some of them might be promising candidates to generate and support sub-2 nm sized MNPs with uniform distribution, which is the key to attaining high catalytic performance [38][39][40][41]. We studied the tenability of organosiloxane precursors with TEOS in the rational synthesis of PMOs [41]. Very recently, we also synthesized 1,3-bis(3-(triethoxysilyl) propyl) thiourea (BTSPT) through a new approach and incorporated it to synthesize a new thiourea-bridged PMO (PMO-TU) with a perfect 2D hexagonal mesostructure (Scheme 1).…”

Section: Introductionmentioning

confidence: 99%

2D Mesoporous Channels of PMO; a Platform for Cluster-Like Pt Synthesis and Catalytic Activity in Nitrophenol Reduction

et al. 2020

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Thiourea-bridged organosiloxane is used to synthesize a periodic mesoporous organosilica (PMO). Since this PMO has an S-enriched surface, owing to thiourea functional groups, it exhibits strong coordination toward Pt ions, and it shows a high tunability in the Pt nanoparticles size. This hybrid mesoporous material is employed as a catalyst in the efficient reduction reaction of 4-nitrophenol to 4-aminophenol at room temperature in an aqueous media.

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“…Porous materials possess brilliant properties, such as high specific surface area (SSA), low weight, excellent storage properties and catalyst supports [1][2][3][4][5][6][7]. Inside various porous materials, catalytic active constituents can be finely produced for alternative catalytic reactions.…”

Section: Introductionmentioning

confidence: 99%

“…Merging periodic mesoporous organosilica with aluminosilica and metal ions was recently reported for generating a catalytically active species toward the aqueous oxidation of dibenzothiophene [45]. Further, Doustkhah et al [7] investigated the uploading of Pd NPs into the pore channels of mesoporous organosilicas-urea for H 2 production from formic acid and 4-nitrophenol (4-NP) reduction.…”

Section: Introductionmentioning

confidence: 99%

Study on catalytic efficiency of platinum and silver nanoparticles confined in nanosized channels of a 3-D mesostructured silica

et al. 2020

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A scalable route to encapsulate homogeneously fine Pt and Ag nanoparticles (NPs) inside amine-functionalized KIT-6 mesochannels via two different reduction routes as heterogeneous mesoporous catalysts is demonstrated. The active amine groups functionalized KIT-6 mesochannels act as anchor sites to immobilize the homogeneous Pt and Ag NPs catalysts with small-sized NPs of approximately 6.0 and 3.0 nm, respectively. The catalysts were fully characterized, and the surface areas were relatively decreased after deposition of the metals NPs. Even after metal NPs deposition, the mesochannels are readily accessible for enhancing their catalytic activity. The meso-KIT-6-Pt catalyst synthesized with ascorbic acid (AA) reduction route shows a higher catalytic efficiency for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) with a reaction rate almost 2 times higher than that of the meso-KIT-6-Ag synthesized using formaldehyde. The as-prepared mesoporous catalysts exhibit a good reusability, with a high catalytic efficiency for at least 5 successive cycles without an obvious loss in their catalytic activity. The influences of reaction parameters, such as catalyst dose, reaction temperarture and nature of solvent on the catalytic performance of the mesoporous catalysts are of the main study.

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Organosiloxane tunability in mesoporous organosilica and punctuated Pd nanoparticles growth; theory and experiment

Cited by 62 publications

References 37 publications

Controllable H2 Generation by Formic Acid Decomposition on a Novel Pd/Templated Carbon Catalyst

Controllable H2 Generation by Formic Acid Decomposition on a Novel Pd/Templated Carbon Catalyst

2D Mesoporous Channels of PMO; a Platform for Cluster-Like Pt Synthesis and Catalytic Activity in Nitrophenol Reduction

Study on catalytic efficiency of platinum and silver nanoparticles confined in nanosized channels of a 3-D mesostructured silica

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