scholarly journals New Insights for the Future Design of Composites Composed of Hydrochar and Zeolite for Developing Advanced Biofuels from Cranberry Pomace

Energies ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 6600
Author(s):  
Omid Norouzi ◽  
Mohammad Heidari ◽  
Mario M. Martinez ◽  
Animesh Dutta
Keyword(s):  
High Surface ◽  
Coke Formation ◽  
High Surface Area ◽  
Chemical Properties ◽  
Catalytic Performance ◽  
Hydroxyl Groups ◽  
Advanced Biofuels ◽  
Operational Conditions ◽  
Future Design ◽  
Cellulosic Sugars

This study provides fundamental insight and offers a promising catalytic hydrothermal method to harness cranberry pomace as a potential bioenergy and/or hydrochar source. The physical and chemical properties of Canadian cranberry pomace, supplied by Fruit d’Or Inc., were examined and the optimum operational conditions, in terms of biocrude yield, were obtained by the I-optimal matrix of Design Expert 11. Afterward, cranberry pomace hydrochar (CPH) and zeolite were separately introduced to the hydrothermal liquefaction (HTL) process to investigate the benefits and disadvantages associated with their catalytic activity. CPH was found to be a better host than zeolite to accommodate cellulosic sugars and showed great catalytic performance in producing hydrocarbons. However, high amounts of corrosive amino and aliphatic acids hinder the practical application of CPH as a catalyst. Alternatively, zeolite, as a commercial high surface area catalyst, had a higher activity for deoxygenation of compounds containing carbonyl, carboxyl, and hydroxyl groups than CPH and resulted in higher selectivity of phenols. Due to the low hydrothermal structural stability, coke formation, and narrow pore size distribution, further activations and modifications are needed to improve the catalytic behavior of zeolite. Our results suggest that a composite composed of CPH and zeolite can resolve the abovementioned limitations and help with the development and commercialization of advanced biofuels from cranberry pomace.

One-Pot Synthesis of Platinum Nanodendrites with Enhanced Catalytic Performance for Methanol Oxidation Reaction

NANO ◽  
2015 ◽  
Vol 10 (07) ◽  
pp. 1550106 ◽  
Author(s):  
Shenshen Ouyang ◽  
Linfei Wang ◽  
Jing Cui ◽  
Haibo Shi ◽  
Tao Wang ◽  
...  
Keyword(s):  
Methanol Oxidation ◽  
Oxidation Reaction ◽  
Hydrothermal Reaction ◽  
High Surface ◽  
High Surface Area ◽  
Chemical Properties ◽  
Catalytic Performance ◽  
Metal Nanostructures ◽  
Methanol Oxidation Reaction ◽  
One Pot

Controlling the synthesis of noble metal nanostructures with highly branched morphology to obtain specific physical and chemical properties has attracted much attention. This paper reports the synthesis of 3D Pt nanodendrites with controlled architectures (multibranched) by a simple one-pot hydrothermal reaction in the presence of fructose. At high reaction temperature, fructose not only acts as a reducing agent, but also forms a hydrothermal carbon, which, as a capping agent, is absorbed on the surface of metal nanocrystals and induces the anisotropic growth of Pt nanodendrites. The prepared Pt nanodendrites are highly porous, and have self-supported nanoarchitectures with a high surface area and a number of absorption sites for reactant molecules. The Pt nanodendrites exhibit a higher electrocatalytic activity and stability than commercial Pt / C for methanol oxidation reaction.

In Situ microscopy of the anodic etching of silicon

1995 ◽  
Vol 53 ◽  
pp. 232-233
Author(s):  
Frances M. Ross ◽  
Peter C. Searson
Keyword(s):  
Composite Structures ◽  
High Surface ◽  
High Surface Area ◽  
Chemical Properties ◽  
Selective Etching ◽  
Silicon On Insulator ◽  
Second Phase ◽  
Porous Layers ◽  
New Class ◽  
Porous Semiconductors

Porous semiconductors represent a relatively new class of materials formed by the selective etching of a single or polycrystalline substrate. Although porous silicon has received considerable attention due to its novel optical properties1, porous layers can be formed in other semiconductors such as GaAs and GaP. These materials are characterised by very high surface area and by electrical, optical and chemical properties that may differ considerably from bulk. The properties depend on the pore morphology, which can be controlled by adjusting the processing conditions and the dopant concentration. A number of novel structures can be fabricated using selective etching. For example, self-supporting membranes can be made by growing pores through a wafer, films with modulated pore structure can be fabricated by varying the applied potential during growth, composite structures can be prepared by depositing a second phase into the pores and silicon-on-insulator structures can be formed by oxidising a buried porous layer. In all these applications the ability to grow nanostructures controllably is critical.

Recent trends in carbon nanotubes based prostate cancer therapy: A biomedical hybrid for diagnosis and treatment

2021 ◽  
Vol 18 ◽  
Author(s):  
Raja Murugesan ◽  
Sureshkumar Raman
Keyword(s):  
Prostate Cancer ◽  
Carbon Nanotubes ◽  
Drug Delivery ◽  
Drug Loading ◽  
High Surface ◽  
High Surface Area ◽  
High Capacity ◽  
Chemical Properties ◽  
Diagnosis And Treatment ◽  
High Level

: At present treatment methods for cancer are limited, partially due to the solubility, poor cellular distribution of drug molecules and, the incapability of drugs to annoy the cellular barriers. Carbon nanotubes (CNTs) generally have excellent physio-chemical properties, which include high-level penetration into the cell membrane, high surface area and high capacity of drug loading by in circulating modification with bio-molecules, project them as an appropriate candidate to diagnose and deliver drugs to prostate cancer (PCa). Additionally, the chemically modified CNTs which have excellent 'Biosensing' properties therefore makes it easy for detecting PCa without fluorescent agent and thus targets the particular site of PCa and also, Drug delivery can accomplish a high efficacy, enhanced permeability with less toxic effects. While CNTs have been mainly engaged in cancer treatment, a few studies are focussed on the diagnosis and treatment of PCa. Here, we detailly reviewed the current progress of the CNTs based diagnosis and targeted drug delivery system for managing and curing PCa.

Efficient and Reusable Silica Gel Supported Metal Ionic Liquid Catalysts for Palmitic Acid Esterification to Biodiesel

2021 ◽  
Vol 43 (1) ◽  
pp. 1-1
Author(s):  
Guo Yingwei Guo Yingwei ◽  
Chen Xuedan Chen Xuedan ◽  
Yan Shiting Yan Shiting ◽  
Zhang Zhengliang Zhang Zhengliang ◽  
Chen Yuqin Chen Yuqin ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Palmitic Acid ◽  
Silica Gel ◽  
High Surface ◽  
High Surface Area ◽  
Kinetic Studies ◽  
Catalytic Performance ◽  
Reaction Conditions ◽  
Acid Esterification ◽  
Supported Metal

A series of silica gel (SG) supported metal ionic liquid catalysts (x[Bmim]Cl-CrCl3/SG) were synthesized and exploited for the esterification of palmitic acid (PA) with methanol (ML) to produce biodiesel efficiently. The 10%[Bmim]Cl-CrCl3/SG catalyst with high surface area and desirable acidity exhibited the best catalytic performance and reusability after six consecutive running cycles. Based on the response surface analysis, the optimal reaction conditions were obtained as follows: methanol/acid mole ratio = 11:1 mol/mol, catalyst amount = 5.3 wt%, reaction time = 65 min, as well as reaction temperature = 373 K, reaching to a biodiesel yield of 96.1%. Further kinetic studies demonstrated that the esterification of PA with ML obeyed 1.41 order kinetics for acid concentration with the activation energy of 16.88 kJ/mol

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.

scholarly journals Atomically Dispersed M-N-C Catalysts in Proton Exchange Membrane Fuel Cells: Recent Progress and Perspectives

2021 ◽  
Vol 308 ◽  
pp. 01019
Author(s):  
Haoran Kong ◽  
Jiarong Liu ◽  
Yu Yue
Keyword(s):  
Fuel Cells ◽  
Cost Effectiveness ◽  
Proton Exchange Membrane ◽  
High Surface ◽  
High Surface Area ◽  
Chemical Properties ◽  
Proton Exchange ◽  
Synthesis Methods ◽  
Zeolitic Imidazolate Framework ◽  
Exchange Membrane

The selection of oxygen reduction reaction (ORR) catalysts plays a key role in enhancing the performance of proton exchange membrane fuel cells (PEMFCs). To optimize the energy conversion technology in PEMFCs and improve the cost-effectiveness of ORR catalysts, atomically dispersed metal-nitrogen-carbon (M-N-C) catalyst is regarded as one of the most promising materials to replace Pt-based catalysts. In this review, we summarize the advantages of atomically dispersed M-N-C catalysts in both physical and chemical properties, including controllable dimensions, ease of accessibility, high surface area and excellent conductivity. Additionally, the unique merits of their cost-effectiveness are also described by a concise comparison with other ORR catalysts. Subsequently, some of its main synthesis methods are based on the most commonly used zeolitic imidazolate framework (ZIF) precursor. Several other precursors involve carbon, nitrogen, and one or more active transition metals (mainly iron or cobalt) are introduced briefly. Although there are a variety of synthesis methods, all these methods are in line with pyrolysis technology. Then, the recent advancements of atomically dispersed M-N-C catalysts related to their development and application of Fe-N-C, Mn-N-C, and Co-N-C catalysts are comprehensively described. Finally, based on some common M-N-C catalysts, many improvement ideas are also proposed. The focus is on how to control the negative reaction in Fe-N-C catalysts, improve the activity of Co-N-C catalysts and Mn-N-C catalysts, and find more suitable transition metal materials to prepare M-N-C catalysts.

NANOCELLULOSE AND ITS POTENTIAL USE FOR SUSTAINABLE INDUSTRIAL APPLICATIONS

2020 ◽  
Vol 50 (2) ◽  
pp. 59-64
Author(s):  
Carlos Negro ◽  
Ana Balea Martín ◽  
Jose Luis Sanchez-Salvador ◽  
Cristina Campano ◽  
Elena Fuente ◽  
...  
Keyword(s):  
High Surface ◽  
High Surface Area ◽  
Industrial Applications ◽  
High Reactivity ◽  
Environmental Benefits ◽  
Hydroxyl Groups ◽  
Paper Briefly ◽  
Potential Availability ◽  
Potential Use ◽  
Market Perspective

Nanocellulose (NC) and its wide applications have attracted high attention due to its desirable properties such as high surface area, extraordinary mechanical properties, high reactivity and easy modification of NC surface due to the presence of primary hydroxyl groups. NC also presents several environmental benefits, including high potential availability because its production is coming from natural sources, renewability and nontoxicity. This paper briefly summarizes some of the activities of the research group “Cellulose, Paper and Water Advanced Treatments” from Complutense University of Madrid that were presented in CAIQ 2019, including the main types of NC, the production processes and their characterization. Additionally, the most promising NC applications are described such as for paper and board, for wastewater treatment, food and cement-based materials. Moreover, a market perspective of NC is also presented.

Efficient and Reusable Silica Gel Supported Metal Ionic Liquid Catalysts for Palmitic Acid Esterification to Biodiesel

2021 ◽  
Vol 43 (1) ◽  
pp. 1-1
Author(s):  
Guo Yingwei Guo Yingwei ◽  
Chen Xuedan Chen Xuedan ◽  
Yan Shiting Yan Shiting ◽  
Zhang Zhengliang Zhang Zhengliang ◽  
Chen Yuqin Chen Yuqin ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Palmitic Acid ◽  
Silica Gel ◽  
High Surface ◽  
High Surface Area ◽  
Kinetic Studies ◽  
Catalytic Performance ◽  
Reaction Conditions ◽  
Acid Esterification ◽  
Supported Metal

A series of silica gel (SG) supported metal ionic liquid catalysts (x[Bmim]Cl-CrCl3/SG) were synthesized and exploited for the esterification of palmitic acid (PA) with methanol (ML) to produce biodiesel efficiently. The 10%[Bmim]Cl-CrCl3/SG catalyst with high surface area and desirable acidity exhibited the best catalytic performance and reusability after six consecutive running cycles. Based on the response surface analysis, the optimal reaction conditions were obtained as follows: methanol/acid mole ratio = 11:1 mol/mol, catalyst amount = 5.3 wt%, reaction time = 65 min, as well as reaction temperature = 373 K, reaching to a biodiesel yield of 96.1%. Further kinetic studies demonstrated that the esterification of PA with ML obeyed 1.41 order kinetics for acid concentration with the activation energy of 16.88 kJ/mol

scholarly journals Metal Nanoparticles as Green Catalysts

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3602 ◽  
Author(s):  
Neel Narayan ◽  
Ashokkumar Meiyazhagan ◽  
Robert Vajtai
Keyword(s):  
Catalytic Activity ◽  
Composite Materials ◽  
Green Synthesis ◽  
Metal Nanoparticles ◽  
Surface Area ◽  
Significant Role ◽  
High Surface ◽  
High Surface Area ◽  
Catalytic Performance ◽  
Materials Development

Nanoparticles play a significant role in various fields ranging from electronics to composite materials development. Among them, metal nanoparticles have attracted much attention in recent decades due to their high surface area, selectivity, tunable morphologies, and remarkable catalytic activity. In this review, we discuss various possibilities for the synthesis of different metal nanoparticles; specifically, we address some of the green synthesis approaches. In the second part of the paper, we review the catalytic performance of the most commonly used metal nanoparticles and we explore a few roadblocks to the commercialization of the developed metal nanoparticles as efficient catalysts.

scholarly journals Catalytic Performance of SBA-15-Supported Poly (Styrenesulfonic Acid) in the Esterification of Acetic Acid with n-Heptanol

2020 ◽  
Vol 10 (17) ◽  
pp. 5835
Author(s):  
Abdulaziz Ali Alghamdi ◽  
Yahya Musawi Mrair ◽  
Fahad A. Alharthi ◽  
Abdel-Basit Al-Odayni
Keyword(s):  
Acetic Acid ◽  
Sulfonic Acid ◽  
Active Sites ◽  
Structural Characteristics ◽  
High Surface ◽  
High Surface Area ◽  
Reaction Times ◽  
Hydrophobic Surface ◽  
Catalytic Performance ◽  
Catalyst Load

A polystyrene sulfonic acid-functionalized mesoporous silica (SBA-15-PSSA) catalyst was synthesized via an established multistep route, employing 2-bromo-2-methylpropionyl bromide as initiator of atom transfer radical polymerization. Fourier-transform infrared spectroscopy, thermogravimetric/differential thermal, Brunauer–Emmett–Teller, and transmission electron microscopy analyses revealed outstanding structural characteristics of the catalyst, including highly ordered mesopores, high surface area (726 m2/g), and adequate estimated concentrations of active sites (0.70 mmol H+/g). SBA-15-PSSA’s catalytic performance was evaluated in the esterification of acetic acid and n-heptanol as a model system at various temperatures (50–110 °C), catalyst loads (0.1–0.3 g), and reaction times (0–160 min). The conversion percentage of acetic acid was found to increase with the temperature, catalyst load, and reaction time. Furthermore, results indicated a fast conversion in the first 20 min of the reaction, with remarkable conversion values at 110 °C, reaching 86%, 94%, and 97% when the catalyst load was 0.1, 0.2, and 0.3 g, respectively; notably, at this temperature, 100% conversation was achieved after 60 min. At 110 °C, the reaction conducted in the presence of 0.3 g of catalyst displayed more than 6.4 times the efficiency of the uncatalyzed reaction. Such activity is explained by the concomitant presence in the polymer of strong sulfonic acid moieties and a relatively high hydrophobic surface, with adequate numbers of active sites for ester production.

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