scholarly journals Acylation of Anisole With Benzoyl Chloride Over Rapidly Synthesized Fly Ash–Based HBEA Zeolite

2021 ◽  
Vol 9 ◽  
Author(s):  
Alechine E. Ameh ◽  
Nicholas M. Musyoka ◽  
Oluwaseun Oyekola ◽  
Benoit Louis ◽  
Leslie F. Petrik
Keyword(s):  
Fly Ash ◽  
Hydrothermal Synthesis ◽  
Surface Area ◽  
Benzoyl Chloride ◽  
High Surface ◽  
High Surface Area ◽  
Strong Acid ◽  
Acid Sites ◽  
Synthesis Time ◽  
Strong Acid Sites

Stable HBEA zeolite with high surface area and strong acid sites was synthesized from coal fly ash–based silica extract via indirect hydrothermal synthesis. The rapid HBEA hydrothermal crystallization times of 8, 10, and 12 h were achieved through a reduced molar water fraction in the synthesis composition. The HBEA zeolites prepared from fly ash silica extract exhibited well-defined spheroidal-shaped crystal morphology with uniform particle sizes of 192, 190, or 239 nm obtained after 8, 10, or 12 h of synthesis time, respectively. The high surface area and the microporous area of 702 and 722 m2/g were achieved as a function of shorter hydrothermal synthesis durations (10 and 24 h, respectively) compared to 48 or 72 h, which resulted in HBEA zeolites with lower surface areas of 538 and 670 m2/g. Likewise, temperature-programmed desorption measurements of fly ash–based HBEA zeolites revealed the presence of weak and strong acid sites in the zeolite. The submicron crystal sizes with a well-defined porosity of HBEA zeolites enhanced the diffusion of anisole and benzoyl chloride molecules toward the active acid sites and hence showed better conversion and selectivity in acylation products. High conversion of benzoyl chloride with anisole was achieved, reaching up to 83% with a 93–96% selectivity toward 4-methoxyacetophenone.

scholarly journals STUDY ON CONVERSION OF VEGETABLE OIL DEODORIZER DISTILLATE TO BIODIESEL USING MESOPOROUS OXO-PHOSPHATED SULFATED ZIRCONIA

2017 ◽  
Vol 55 (1) ◽  
pp. 44
Author(s):  
Vuong Van Pham ◽  
Hong Khanh Dieu Nguyen
Keyword(s):  
Vegetable Oil ◽  
Sulfated Zirconia ◽  
High Surface ◽  
High Surface Area ◽  
Strong Acid ◽  
Acid Sites ◽  
Deodorizer Distillate ◽  
Synthesis Process ◽  
Biodiesel Synthesis ◽  
Strong Acid Sites

Mesoporous oxo - phosphated sulfated zirconia (m-PSZ) were applied for converting vegetable oil deodorizer distillate to biodiesel in one-step reaction. The catalyst possessed mesopores, high surface area and strong acid sites while the feedstock contained mainly free fatty acids. Many investigations were established for finding the most suitable conditions of the biodiesel synthesis process.

scholarly journals MIL-101(Cr) for CO2 Conversion into Cyclic Carbonates, Under Solvent and Co-Catalyst Free Mild Reaction Conditions

Catalysts ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 453
Author(s):  
Emmanuelia Akimana ◽  
Jichao Wang ◽  
Natalya V. Likhanova ◽  
Somboon Chaemchuen ◽  
Francis Verpoort
Keyword(s):  
Ring Opening ◽  
High Surface ◽  
High Surface Area ◽  
Strong Acid ◽  
Catalytic Performance ◽  
Acid Sites ◽  
Cyclic Carbonates ◽  
Reaction Conditions ◽  
Co Catalyst ◽  
Strong Acid Sites

Mild reaction conditions (nearly room temperature and atmospheric CO2 pressure) for the cycloaddition of CO2 with epoxides to produce cyclic carbonates were investigated applying MIL-101(Cr) as a catalyst. The MIL-101 catalyst contains strong acid sites, which promote the ring-opening of the epoxide substrate. Moreover, the high surface area, enabling the adsorption of more CO2 (substrate), combined with a large pore size of the catalyst is essential for the catalytic performance. Additionally, epoxide substrates bearing electron-withdrawing substituents or having a low boiling point demonstrated an excellent conversion towards the cyclic carbonates. MIL-101(Cr) for the cycloaddition of carbon dioxide with epoxides is demonstrated to be a robust and stable catalyst able to be re-used at least five times without loss in activity.

Hydrophobic High Surface Area Zeolites Derived from Fly Ash for Oil Spill Remediation

2013 ◽  
Vol 47 (11) ◽  
pp. 5843-5850 ◽  
Author(s):  
Tamilselvan Sakthivel ◽  
David L. Reid ◽  
Ian Goldstein ◽  
Larry Hench ◽  
Sudipta Seal
Keyword(s):  
Fly Ash ◽  
Surface Area ◽  
Oil Spill ◽  
High Surface ◽  
High Surface Area ◽  
Oil Spill Remediation

Carbon Dioxide Sequestration Using Activated Carbon From Agro Waste-Waste Bamboo

2021 ◽  
Author(s):  
Emmanuel Ayodele ◽  
Victoria Ezeagwula ◽  
Precious Igbokwubiri
Keyword(s):  
Activated Carbon ◽  
Fly Ash ◽  
Greenhouse Gases ◽  
Surface Area ◽  
Carbon Capture ◽  
Agricultural Waste ◽  
High Surface ◽  
Research Work ◽  
High Surface Area ◽  
Bet Surface Area

Abstract Bamboo trees are one of the fastest growing trees in tropical rainforests around the world, they have various uses ranging from construction to fly ash generation used in oil and gas cementing, to development of activated carbon which is one of the latest uses of bamboo trees. This paper focuses on development of activated carbon from bamboo trees for carbon capture and sequestration. The need for improved air quality becomes imperative as the SDG Goal 12 and SDG Goal13 implies. One of the major greenhouse gases is CO2 which accounts for over 80% of greenhouse gases in the environment. Eliminating the greenhouse gases without adding another pollutant to the environment is highly sought after in the 21st century. Bamboo trees are mostly seen as agricultural waste with the advent of scaffolding and other support systems being in the construction industry. Instead of burning bamboo trees or using them for cooking in the local communities which in turn generates CO2 and fly ash, an alternative was considered in this research work, which is the usage of bamboo trees to generate activated, moderately porous and high surface area carbon for extracting CO2 from various CO2 discharge sources atmosphere and for water purification. This paper focuses on the quality testing of activated carbon that can effectively absorb CO2. The porosity, pore volume, bulk volume, and BET surface area were measured. The porosity of the activated carbon is 27%, BET surface area as 1260m²/g. Fixed carbon was 11.7%, Volatility 73%, ash content 1.7%.

scholarly journals Impact of Thermal Treatment of Nb2O5 on Its Performance in Glucose Dehydration to 5-Hydroxymethylfurfural in Water

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1685
Author(s):  
Katarzyna Morawa Eblagon ◽  
Anna Malaika ◽  
Karolina Ptaszynska ◽  
Manuel Fernando R. Pereira ◽  
José Luís Figueiredo
Keyword(s):  
Thermal Treatment ◽  
Surface Area ◽  
Pure Water ◽  
High Surface ◽  
High Surface Area ◽  
Acid Sites ◽  
High Ratio ◽  
Total Acidity ◽  
One Pot ◽  
Niobic Acid

The cascade dehydration of glucose to 5-hydroxymethylfurfural (HMF) was carried out in water over a series of Nb2O5 catalysts, which were derived from the thermal treatment of niobic acid at 300 and 550 °C, under air or inert atmosphere. Amorphous niobic acid showed high surface area (366 m2/g) and large acidity (2.35 mmol/g). With increasing the temperature of the thermal treatment up to 550 °C, the amorphous Nb2O5 was gradually transformed into a pseudohexagonal phase, resulting in a decrease in surface area (27–39 m2/g) and total acidity (0.05–0.19 mmol/g). The catalysts’ performance in cascade dehydration of glucose realized in pure water was strongly influenced by the total acidity of these materials. A remarkable yield of 37% HMF in one-pot reaction in water was achieved using mesoporous amorphous niobium oxide prepared by thermal treatment of niobic acid at 300 °C in air. The best-performing catalyst displayed a total acidity lower than niobic acid (1.69 mmol/g) which afforded a correct balance between a high glucose conversion and limited further conversion of the target product to numerous polymers and humins. On the other hand, the treatment of niobic acid at 550 °C, independently of the atmosphere used during the sample preparation (i.e., air or N2), resulted in Nb2O5 catalysts with a high ratio of Lewis to Brønsted acid sites and poor total acidity. These materials excelled at catalyzing the isomerization step in the tandem process.

One-Step Hydrothermal Synthesis of MoS2 Nano-Flowers with High Surface Area and Crystalline

2012 ◽  
Vol 531-532 ◽  
pp. 508-511 ◽  
Author(s):  
Yan Juan Li ◽  
Nan Li ◽  
Xiao Yan ◽  
Yue Chi ◽  
Qing Yuan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Hydrothermal Synthesis ◽  
Surface Area ◽  
Ph Value ◽  
High Surface ◽  
High Surface Area ◽  
Ammonium Molybdate ◽  
Molar Ratio ◽  
Sulfur Source ◽  
One Step

One-step and controlled pH hydrothermal synthesis of transition metal disulfide using double molybdenum sources to synthesize MoS2 nano-flowers at low temperature was first reported. Anhydrous molybdenum pentachloride (MoCl5) and four sulfur ammonium molybdate ((NH4) 6Mo7O24•4H2O) were the molybdenum source and CS (NH2) 2 was the sulfur source. Through hydrothermal method, MoS2 was obtained at 180 °C. The pH value of system was controlled by adjusting the molar ratio of MoCl5 and (NH4) 6Mo7O24•4H2O. The products were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), surface area (BET) and transmission electron microscopy (TEM). The results show that the products were hexagonal MoS2 with a high crystalline and flower-like structure consisted of small particles. The thickness of petals is a few to tens of nanometers. By changing the molar ratio of molybdenum sources, the resultant phase from the mixed phase transited to the pure phase and the purity of synthetic MoS2 crystal increaseed.

scholarly journals Hydrothermal synthesis of high surface area CuCrO2 for H2 production by methanol steam reforming

RSC Advances ◽  
2021 ◽  
Vol 11 (21) ◽  
pp. 12607-12613
Author(s):  
Rong-Jun Huang ◽  
Subramanian Sakthinathan ◽  
Te-Wei Chiu ◽  
Chaofang Dong
Keyword(s):  
Hydrothermal Synthesis ◽  
Surface Area ◽  
Steam Reforming ◽  
High Surface ◽  
High Surface Area ◽  
H2 Production ◽  
Methanol Steam Reforming

Hydrothermal synthesis of CuCrO2 nanopowder for H2 production by methanol steam reforming.

scholarly journals Synthesis of ZSM-5 Zeolite Using Coal Fly Ash as an Additive for the Methanol to Propylene (MTP) Reaction

Catalysts ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 788 ◽  
Author(s):  
Rui Feng ◽  
Kening Chen ◽  
Xinlong Yan ◽  
Xiaoyan Hu ◽  
Yixin Zhang ◽  
...  
Keyword(s):  
Fly Ash ◽  
Coal Gasification ◽  
Coal Fly Ash ◽  
Strong Acid ◽  
Acid Sites ◽  
Raw Material ◽  
X Ray Diffraction ◽  
Strong Acid Sites ◽  
Optimized Conditions ◽  
N2 Sorption

Using ZSM-5 zeolites as catalysts for the methanol to propylene (MTP) reaction is being widely investigated and has been industrially applied. In this study, pure ZSM-5 zeolite was successfully synthesized by a direct hydrothermal method using the fly ash of coal gasification as an additional raw material. Various analysis methods such as X-ray diffraction, N2 sorption, scanning electron microscopy, and infrared spectroscopy, were employed to characterize the physicochemical properties of parent and modified zeolites. Then, the prepared ZSM-5 catalysts were tested in the MTP reaction. The results showed that pure ZSM-5 could be directly synthesized in the optimized conditions using fly ash as additional silicon and aluminum sources, and those ZSM-5 catalysts turned out to be candidate catalysts for the MTP reaction. Whereas their catalytic lifetimes were not good enough due to the strong acid sites and needed improving.

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