A porous Brønsted superacid as an efficient and durable solid catalyst

2018 ◽  
Vol 6 (38) ◽  
pp. 18712-18719 ◽  
Author(s):  
Qi Sun ◽  
Kewei Hu ◽  
Kunyue Leng ◽  
Xianfeng Yi ◽  
Briana Aguila ◽  
...  
Keyword(s):  
Surface Area ◽  
Active Sites ◽  
High Surface ◽  
High Surface Area ◽  
Solid Catalyst ◽  
Chemical Transformations ◽  
Catalytic Activities ◽  
Industrial Chemical

A porous superacid material with a high surface area and abundant accessible active sites is rationally designed, showing outstanding catalytic activities and durability in industrial chemical transformations.

Spidery catalyst for the synthesis of quinazoline-2,4(1H,3H)-diones

2016 ◽  
Vol 6 (5) ◽  
pp. 1435-1441 ◽  
Author(s):  
Seyed Mohsen Sadeghzadeh
Keyword(s):  
Surface Area ◽  
Active Sites ◽  
High Surface ◽  
High Surface Area

In this study, a novel fibrous nanosilica (KCC-1) based nanocatalyst (Au, Pd, and Cu) with a high surface area and easy accessibility of active sites was successfully developed by a facile approach.

scholarly journals Catalytic Cracking of n-Hexadecane Using Carbon Nanostructures/Nano-Zeolite-Y Composite Catalyst

Catalysts ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1385
Author(s):  
Botagoz Zhuman ◽  
Shaheen Fatima Anis ◽  
Saepurahman ◽  
Gnanapragasam Singravel ◽  
Raed Hashaikeh
Keyword(s):  
Surface Area ◽  
Catalytic Cracking ◽  
Carbon Nanostructures ◽  
Active Sites ◽  
Zeolite Y ◽  
High Surface ◽  
High Surface Area ◽  
Composite Catalyst ◽  
Homogeneous Distribution ◽  
Binding Material

Zeolite-based catalysts are usually utilized in the form of a composite with binders, such as alumina, silica, clay, and others. However, these binders are usually known to block the accessibility of the active sites in zeolites, leading to a decreased effective surface area and agglomeration of zeolite particles. The aim of this work is to utilize carbon nanostructures (CNS) as a binding material for nano-zeolite-Y particles. The unique properties of CNS, such as its high surface area, thermal stability, and flexibility of its fibrous structure, makes it a promising material to hold and bind the nano-zeolite particles, yet with a contemporaneous accessibility of the reactants to the porous zeolite structure. In the current study, a nano-zeolite-Y/CNS composite catalyst was fabricated through a ball milling approach. The catalyst possesses a high surface area of 834 m2/g, which is significantly higher than the conventional commercial cracking catalysts. Using CNS as a binding material provided homogeneous distribution of the zeolite nanoparticles with high accessibility to the active sites and good mechanical stability. In addition, CNS was found to be an effective binding material for nano-zeolite particles, solving their major drawback of agglomeration. The nano-zeolite-Y/CNS composite showed 80% conversion for hexadecane catalytic cracking into valuable olefins and hydrogen gas, which was 14% higher compared to that of pure nano-zeolite-Y particles.

scholarly journals Ultrasonic-assisted preparation of highly active Co3O4/MCM-41 adsorbent and its desulfurization performance for low H2S concentration gas

RSC Advances ◽  
2020 ◽  
Vol 10 (50) ◽  
pp. 30214-30222
Author(s):  
Bolong Jiang ◽  
Jiaojing Zhang ◽  
Yanguang Chen ◽  
Hua Song ◽  
Tianzhen Hao ◽  
...  
Keyword(s):  
Surface Area ◽  
Active Sites ◽  
High Surface ◽  
High Surface Area ◽  
Highly Active ◽  
Ultrasonic Assisted ◽  
Sulfur Capacity ◽  
Mcm 41

Co3O4/MCM-41 adsorbent with high surface area and more active sites was successfully prepared by ultrasonic assisted impregnation (UAI) technology and it has been found that the sulfur capacity was improved by 33.2% because of ultrasonication.

scholarly journals Bifunctional Materials for CO₂ Adsorption: Short Review

2021 ◽  
Vol 7 (2) ◽  
pp. 15-19
Author(s):  
S. M. Yusof ◽  
L. P. Teh
Keyword(s):  
Surface Area ◽  
Active Sites ◽  
Co2 Adsorption ◽  
High Surface ◽  
Co Adsorption ◽  
High Surface Area ◽  
Short Review ◽  
High Dispersion ◽  
High Porosity ◽  
Adsorption Performance

In recent years, there has been growing interest in adsorbents with high surface area, high porosity, high stability and high selectivity for CO2 adsorption. By the incorporation of the additive on the supports such as zeolite, silica, and carbon, the physicochemical properties of the adsorbent and CO2 adsorption performance can be enhanced. In this review, we focus on the overview of bifunctional materials (BFMs) for CO2 adsorption. The findings of this study suggests that the high surface area and high porosity of the support provide a good medium for high dispersion and accessibility of additives (amine or metal oxide), enhancing the CO2 adsorption efficiency. The excessive additive however may lead to a decrease of CO2 adsorption performance due to pore blockage and the decrease of active sites for CO2 interactions. The synergistic relationship of the supporting material and additive is significant towards the enhancement of CO2 adsorption.

scholarly journals Synthesis and characterization of a novel CNT-FeNi3/DFNS/Cu(ii) magnetic nanocomposite for the photocatalytic degradation of tetracycline in wastewater

RSC Advances ◽  
2019 ◽  
Vol 9 (60) ◽  
pp. 35022-35032 ◽  
Author(s):  
Yanhua Zhao ◽  
Jie Juan Tang ◽  
Alireza Motavalizadehkakhky ◽  
Saeid Kakooei ◽  
Seyed Mohsen Sadeghzadeh
Keyword(s):  
Photocatalytic Degradation ◽  
Surface Area ◽  
Active Sites ◽  
High Surface ◽  
High Surface Area ◽  
Magnetic Nanocomposite ◽  
Synthesis And Characterization

Herein, Cu(ii) complexes were anchored within the nanospaces of a magnetic fibrous silicate with a high surface area and easily accessible active sites via a facile approach, leading to the successful synthesis of a novel potent nanocatalyst (FeNi3/DFNS/Cu).

A new paradigm of ultrathin 2D nanomaterial adsorbents in aqueous media: graphene and GO, MoS2, MXenes, and 2D MOFs

2019 ◽  
Vol 7 (28) ◽  
pp. 16598-16621 ◽  
Author(s):  
Pin Zhao ◽  
Meipeng Jian ◽  
Qi Zhang ◽  
Rongming Xu ◽  
Ruiping Liu ◽  
...  
Keyword(s):  
Surface Area ◽  
Active Sites ◽  
High Performance ◽  
High Surface ◽  
Aqueous Media ◽  
High Surface Area ◽  
Atomic Level ◽  
New Paradigm ◽  
2D Nanomaterials

Due to the high surface area, atomic-level thickness, and abundant exposed active sites, 2D nanomaterials are regarded potential high-performance adsorbents. We review four representative nanomaterials, graphene, MoS2, MXenes, and MOFs, for this application.

scholarly journals Synthesizing the High Surface Area g-C3N4 for Greatly Enhanced Hydrogen Production

Catalysts ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 832
Author(s):  
Chengfei Wang ◽  
Tongxin Han ◽  
Chang Xin ◽  
Hui Miao
Keyword(s):  
Photocatalytic Activity ◽  
Hydrogen Production ◽  
Surface Area ◽  
Hydrogen Evolution ◽  
Redox Reaction ◽  
Active Sites ◽  
High Surface ◽  
High Surface Area ◽  
Ambient Atmosphere ◽  
Diffusion Distance

Adjusting the structure of g-C3N4 to significantly enhance its photocatalytic activity has attracted considerable attention. Herein, a novel, sponge-like g-C3N4 with a porous structure is prepared from the annealing of protonated melamine under N2/H2 atmosphere (PH-CN). Compared to bulk g-C3N4 via calcination of melamine under ambient atmosphere (B-CN), PH-CN displays thinner nanosheets and a higher surface area (150.1 m2/g), which is a benefit for shortening the diffusion distance of photoinduced carriers, providing more active sites, and finally favoring the enhancement of the photocatalytic activity. Moreover, it can be clearly observed from the UV-vis spectrum that PH-CN displays better performance for harvesting light compared to B-CN. Additionally, the PH-CN is prepared with a larger band gap of 2.88 eV with the Fermi level and conduction band potential increased and valence band potential decreased, which could promote the water redox reaction. The application experiment results show that the hydrogen evolution rate on PH-CN was nearly 10 times higher than that of B-CN, which was roughly 4104 μmol h−1 g−1. The method shown in this work provides an effective approach to adjust the structure of g-C3N4 with considerable photocatalytic hydrogen evolution activity.

scholarly journals Utilization of carbon nanotube and graphene in electrochemical CO2 reduction

2020 ◽  
Vol 10 (4) ◽  
pp. 5815-5827
Keyword(s):  
Surface Area ◽  
Active Sites ◽  
High Surface ◽  
High Surface Area ◽  
Co2 Reduction ◽  
Value Added ◽  
Vital Role ◽  
Low Carbon ◽  
Support Materials ◽  
Electrochemical Co2 Reduction

The electrochemical reduction of carbon dioxide (ERCO2) driven by renewable energy to produce low-carbon fuels and value-added chemicals has been well known as a way capable of simultaneously solving energy exhaustion and global warming issue. Catalysts play a vital role in low temperature ERCO2, and those well used are single metals, metal oxides and alloys. Due to the characteristics of nanometer size, low resistance, high surface area, chemical stability, special mechanical and electronic properties, some novel carbon nomaterials (e.g. carbon nanotubes (CNTs) and graphene) show excellent properties in ERCO2 as catalysts or supports which can improve the electrochemical performance: activity, selectivity, and stability. Actually, they mostly act as support materials and little directly as catalysts. The specific surface area and the active sites of loaded catalysts can be increased, then the performance is significantly improved. In this work, we will make a review on the progress as to CNTs and graphene as catalysts and supports in ERCO2 in recent years and give the future prospects.

scholarly journals Synthesis of high surface area magnesia by using walnut shell as a template

2019 ◽  
Vol 8 (1) ◽  
pp. 199-206 ◽  
Author(s):  
Asghar Zamani ◽  
Ahmad Poursattar Marjani ◽  
Mojtaba Abedi Mehmandar
Keyword(s):  
Surface Area ◽  
Magnesium Oxide ◽  
Aerobic Oxidation ◽  
High Surface ◽  
High Surface Area ◽  
Magnesium Nitrate ◽  
Walnut Shell ◽  
Solid Catalyst ◽  
Loaded Material ◽  
Adsorption Desorption

Abstract In the present study, high surface area amorphous magnesia was synthesized using walnut shell as a template. This green, simple and useful synthetic protocol was based on the precipitation of magnesium nitrate on biomass in an aqueous phase, followed by calcination. Materials were characterized using X-ray diffraction, scanning electron microscopy (SEM) and N2 adsorption/desorption porosimetry, and the results exhibited high surface area for magnesium oxide. Furthermore, the pore size and surface area of these mesoporous materials can be adjusted by varying the biomass/magnesium nitrate ratio. In addition, magnesium oxide was studied as the support of palladium nanoparticles for the aerobic oxidation of alcohols. We have found out that the resulting Pd-loaded material acts as an effective catalytic system for the aerobic oxidation of benzylic and aliphatic alcohols. The catalyst can be recovered and reused three times without loss of activity. Also, to test the catalytic activity of magnesium oxides as a solid catalyst, we selected Meerwein-Ponndorf-Verley reduction of cyclohexanone with 2-propanol over different magnesium oxides.

scholarly journals Hierarchical Nanostructured Photocatalysts for CO2 Photoreduction

Catalysts ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 370 ◽  
Author(s):  
Hiragond ◽  
Ali ◽  
Sorcar ◽  
In
Keyword(s):  
Surface Area ◽  
Active Sites ◽  
Light Harvesting ◽  
Low Cost ◽  
High Surface ◽  
High Surface Area ◽  
Practical Implementation ◽  
Co2 Photoreduction ◽  
Highly Efficient

Practical implementation of CO2 photoreduction technologies requires low-cost, highly efficient, and robust photocatalysts. High surface area photocatalysts are notable in that they offer abundant active sites and enhanced light harvesting. Here we summarize the progress in CO2 photoreduction with respect to synthesis and application of hierarchical nanostructured photocatalysts.

Sign in / Sign up

Export Citation Format

Share Document