Transition metal/metal oxide modified MCM-41 for pollutant degradation and hydrogen energy production: a review

RSC Advances ◽  
2015 ◽  
Vol 5 (102) ◽  
pp. 83707-83724 ◽  
Author(s):  
Dipti Prava Sahoo ◽  
Dharitri Rath ◽  
Binita Nanda ◽  
K. M. Parida
Keyword(s):  
Catalytic Activity ◽  
Metal Oxide ◽  
Energy Production ◽  
High Surface ◽  
High Surface Area ◽  
Hydrogen Energy ◽  
Pollutant Degradation ◽  
Metal Metal ◽  
Catalytic Applications ◽  
Mcm 41

Metal/metal oxide modified MCM-41 materials are suitable for various catalytic applications. The high surface area, mesoscopic pore size and tunable pore volume of the materials play a key role in enhancing the catalytic activity.

scholarly journals Starch-Based Hybrid Nanomaterials for Environmental Remediation

2021 ◽  
Author(s):  
Ashoka Gamage ◽  
Thiviya Punniamoorthy ◽  
Terrence Madhujith
Keyword(s):  
Metal Oxide ◽  
Environmental Remediation ◽  
Membrane Filtration ◽  
Anthropogenic Activities ◽  
Low Cost ◽  
High Surface ◽  
High Surface Area ◽  
Volume Ratio ◽  
Hybrid Nanomaterials ◽  
Metal Metal

Environmental pollution is becoming a major global issue with increasing anthropogenic activities that release massive toxic pollutants into the land, air, and water. Nanomaterials have gained the most popularity in the last decades over conventional methods because of their high surface area to volume ratio and higher reactivity. Nanomaterials including metal, metal oxide, zero-valent ions, carbonaceous nanomaterials, and polymers function as adsorbents, catalysts, photocatalysts, membrane (filtration), disinfectants, and sensors in the detection and removal of various pollutants such as heavy metals, organic pollutants, dyes, industrial effluents, and pathogenic microbial. Polymer-inorganic hybrid materials or nanocomposites are highly studied for the removal of various contaminants. Starch, a heteropolysaccharide, is a natural biopolymer generally incorporated with other metal, metal oxide, and other polymeric nanoparticles and has been reported in various environmental remediation applications as a low-cost alternative for petroleum-based polymers. Therefore, this chapter mainly highlights the various nanomaterials used in environmental remediation, starch-based hybrid nanomaterials, and their application and limitations.

scholarly journals MCM-41 Supported Co-Based Bimetallic Catalysts for Aqueous Phase Transformation of Glucose to Biochemicals

Processes ◽  
2020 ◽  
Vol 8 (7) ◽  
pp. 843 ◽  
Author(s):  
Somayeh Taghavi ◽  
Elena Ghedini ◽  
Federica Menegazzo ◽  
Michela Signoretto ◽  
Delia Gazzoli ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Bimetallic Catalysts ◽  
High Surface ◽  
High Surface Area ◽  
Mesoporous Structure ◽  
Acid Sites ◽  
Weak Acid ◽  
Reaction Conditions ◽  
Temperature Programmed ◽  
Mcm 41

The transformation of glucose into valuable biochemicals was carried out on different MCM-41-supported metallic and bimetallic (Co, Co-Fe, Co-Mn, Co-Mo) catalysts and under different reaction conditions (150 °C, 3 h; 200 °C, 0.5 h; 250 °C, 0.5 h). All catalysts were characterized using N2 physisorption, Temperature Programmed Reduction (TPR), Raman, X-ray Diffraction (XRD) and Temperature Programmed Desorption (TPD) techniques. According to the N2-physisorption results, a high surface area and mesoporous structure of the support were appropriate for metal dispersion, reactant diffusion and the formation of bioproducts. Reaction conditions, bimetals synergetic effects and the amount and strength of catalyst acid sites were the key factors affecting the catalytic activity and biochemical selectivity. Sever reaction conditions including high temperature and high catalyst acidity led to the formation mainly of solid humins. The NH3-TPD results demonstrated the alteration of acidity in different bimetallic catalysts. The 10Fe10CoSiO2 catalyst (MCM-41 supported 10 wt.%Fe, 10 wt.%Co) possessing weak acid sites displayed the best catalytic activity with the highest carbon balance and desired product selectivity in mild reaction condition. Valuable biochemicals such as fructose, levulinic acid, ethanol and hydroxyacetone were formed over this catalyst.

scholarly journals Flower-Shaped C-Dots/Co3O4{111} Constructed with Dual-Reaction Centers for Enhancement of Fenton-Like Reaction Activity and Peroxymonosulfate Conversion to Sulfate Radical

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 135
Author(s):  
Zhibin Wen ◽  
Qianqian Zhu ◽  
Jiali Zhou ◽  
Shudi Zhao ◽  
Jinnan Wang ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Active Site ◽  
High Surface ◽  
High Surface Area ◽  
Reaction Centers ◽  
Organic Radicals ◽  
The Other ◽  
High Catalytic Activity ◽  
High Adsorption ◽  
High Turnover

Novel flower-shaped C-dots/Co3O4{111} with dual-reaction centers were constructed to improve the Fenton-like reaction activity and peroxymonosulfate (PMS) conversion to sulfate radicals. Due to the exposure of a high surface area and Co3O4{111} facets, flower-shaped C-dots/Co3O4{111} could provide more Co(II) for PMS activation than traditional spherical Co3O4{110}. Meanwhile, PMS was preferred for adsorption on Co3O4{111} facets because of a high adsorption energy and thereby facilitated the electron transfer from Co(II) to PMS. More importantly, the Co–O–C linkage between C-dots and Co3O4{111} induced the formation of the dual-reaction center, which promoted the production of reactive organic radicals (R•). PMS could be directly reduced to SO4−• by R• over C-dots. On the other hand, electron transferred from R• to Co via Co–O–C linkage could accelerate the redox of Co(II)/(III), avoiding the invalid decomposition of PMS. Thus, C-dots doped on Co3O4{111} improved the PMS conversion rate to SO4−• over the single active site, resulting in high turnover numbers (TONs). In addition, TPR analysis indicated that the optimal content of C-dots doped on Co3O4{111} is 2.5%. More than 99% of antibiotics and dyes were degraded over C-dots/Co3O4{111} within 10 min. Even after six cycles, C-dots/Co3O4{111} still remained a high catalytic activity.

scholarly journals Sulfamic acid pyromellitic diamide-functionalized MCM-41 as a multifunctional hybrid catalyst for melting-assisted solvent-free synthesis of bioactive 3,4-dihydropyrimidin-2-(1H)-ones

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ehsan Valiey ◽  
Mohammad G. Dekamin ◽  
Zahra Alirezvani
Keyword(s):  
Structural Characteristics ◽  
Biginelli Reaction ◽  
High Surface ◽  
High Surface Area ◽  
Sulfamic Acid ◽  
Solvent Free ◽  
Biologically Active ◽  
Green Protocol ◽  
Solvent Free Conditions ◽  
Mcm 41

AbstractThis study introduces a practical approach to fabricate a novel hybrid acidic catalyst, namely sulfamic acid pyromellitic diamide-functionalized MCM-41 (MCM-41-APS-PMDA-NHSO3H). Various techniques such as FTIR, TGA, XRD, BET, FESEM, and EDX were used to confirm its structural characteristics. The efficiency of the new MCM-41-APS-PMDA-NHSO3H organosilica nanomaterials, as a heterogenous nanocatalyst, was examined in the synthesis of biologically active 3,4-dihydropyrimidin-2-(1H)-one derivatives under solvent-free conditions. It was found that the nanoporous MCM-41-APS-PMDA-NHSO3H, demonstrating acidic nature and high surface area, can activate all the Biginelli reaction components to afford desired 3,4-dihydropyrimidin-2-(1H)-ones under solvent-free conditions in short reaction time. Furthermore, easy and quick isolation of the new introduced hybrid organosilica from the reaction mixture as well as its reusability with negligible loss of activity in at least five consecutive runs are another advantages of this green protocol.

Design of Transition Metal Oxide and Hybrid Mesoporous Materials

2002 ◽  
Vol 728 ◽  
Author(s):  
Clément Sanchez ◽  
Eduardo L. Crepaldi ◽  
Anne Bouchara ◽  
Florence Cagnol ◽  
David Grosso ◽  
...  
Keyword(s):  
Transition Metal ◽  
Metal Oxide ◽  
High Surface ◽  
High Surface Area ◽  
Directed Assembly ◽  
Optical Quality ◽  
Hybrid Thin Films ◽  
Poly Ethylene ◽  
Inorganic Framework ◽  
Hybrid Mesoporous Materials

AbstractMesostructured transition metal (Ti, Zr, V, Al and Ce-Zr) oxide-based hybrid thin films, templated by poly(ethylene oxide)-based surfactants or block copolymers, have been prepared reproducibly, displaying 2D-hexagonal (p6m) or 2D-centred rectangular (c2m) structure. By carefully adjusting the variables involved it is possible to combine both high organisation and excellent optical quality. TiO2 and ZrO2-based materials show thermal stability up to 400-550°C. The elimination of the template can be conducted efficiently and gives rise to high surface area mesoporous films. For the other metal oxide hybrids the inorganic framework is much more fragile, and requires a precise sequence of post-treatments to be stabilised. In addition, original and homogeneous macrotextures shaped with coral-like, helical or macroporous sieves morphologies have been obtained following a nanotectonic approach based on the template-directed assembly by poly-γ-benzyl-L-glutamate (PBLG) of organically functionalised CeO2 crystalline nanoparticles.

scholarly journals Oxidation of alkyl benzenes by a flavin photooxidation catalyst on nanostructured metal-oxide films

2017 ◽  
Vol 114 (35) ◽  
pp. 9279-9283 ◽  
Author(s):  
Prateek Dongare ◽  
Ian MacKenzie ◽  
Degao Wang ◽  
David A. Nicewicz ◽  
Thomas J. Meyer
Keyword(s):  
Metal Oxide ◽  
Surface Area ◽  
Aromatic Hydrocarbons ◽  
High Surface ◽  
High Surface Area ◽  
Oxide Films ◽  
Flavin Mononucleotide ◽  
Metal Oxide Films ◽  
Alkyl Benzenes ◽  
Nanostructured Metal

We describe here a surface-bound, oxide-based procedure for the photooxidation of a family of aromatic hydrocarbons by a phosphate-bearing flavin mononucleotide (FMN) photocatalyst on high surface area metal-oxide films.

scholarly journals High surface area nitrogen-functionalized Ni nanozymes for efficient peroxidase-like catalytic activity

PLoS ONE ◽  
2021 ◽  
Vol 16 (10) ◽  
pp. e0257777
Author(s):  
Anuja Tripathi ◽  
Kenneth D. Harris ◽  
Anastasia L. Elias
Keyword(s):  
Catalytic Activity ◽  
Plasma Treatment ◽  
Surface Composition ◽  
Point Of Care ◽  
High Surface ◽  
Effective Means ◽  
High Surface Area ◽  
Catalytic Performance ◽  
Optimal Time ◽  
Ammonia Plasma

Nitrogen-functionalization is an effective means of improving the catalytic performances of nanozymes. In the present work, plasma-assisted nitrogen modification of nanocolumnar Ni GLAD films was performed using an ammonia plasma, resulting in an improvement in the peroxidase-like catalytic performance of the porous, nanostructured Ni films. The plasma-treated nanozymes were characterized by TEM, SEM, XRD, and XPS, revealing a nitrogen-rich surface composition. Increased surface wettability was observed after ammonia plasma treatment, and the resulting nitrogen-functionalized Ni GLAD films presented dramatically enhanced peroxidase-like catalytic activity. The optimal time for plasma treatment was determined to be 120 s; when used to catalyze the oxidation of the colorimetric substrate TMB in the presence of H2O2, Ni films subjected to 120 s of plasma treatment yielded a much higher maximum reaction velocity (3.7⊆10−8 M/s vs. 2.3⊆10−8 M/s) and lower Michaelis-Menten coefficient (0.17 mM vs. 0.23 mM) than pristine Ni films with the same morphology. Additionally, we demonstrate the application of the nanozyme in a gravity-driven, continuous catalytic reaction device. Such a controllable plasma treatment strategy may open a new door toward surface-functionalized nanozymes with improved catalytic performance and potential applications in flow-driven point-of-care devices.

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