scholarly journals H3PW12O40/SBA-15 for the Solventless Synthesis of 3-Substituted Indoles

Catalysts ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 409 ◽  
Author(s):  
Tayebee ◽  
Lee ◽  
Frattini ◽  
Rostami
Keyword(s):  
Solid Acid ◽  
Catalytic Efficiency ◽  
Aromatic Aldehydes ◽  
Solid Acid Catalysts ◽  
High Dispersion ◽  
Acid Catalysts ◽  
Strongly Correlated ◽  
Wet Impregnation ◽  
Mild Conditions ◽  
Solventless Synthesis

A family of silica-supported H3PW12O40 (HPW) solid acid catalysts was prepared by wet impregnation of mesoporous SBA-15 and investigated for the solventless synthesis of 3-substituted indoles under mild conditions. Mesoporous SBA-15 facilitated a high dispersion of immobilised H3PW12O40, significantly improving the catalytic efficiency of the heteropolyacid for the desired multi-component transformation. The yield of 3-substituted indoles strongly correlated with HPW loading (which spanned 3.2–51.6 wt %) and corresponding acid strength; the 51.6 wt % HPW/SBA-15 delivered 81% yield of 2-[(1H-indol-3-yl)(phenyl)methyl]malononitrile, approximately five times greater than that of the unsupported HPW, and exhibited a broad substrate scope for aromatic aldehydes.

Structural studies of high dispersion H3PW12O40/SiO2 solid acid catalysts

2006 ◽  
Vol 8 (24) ◽  
pp. 2893 ◽  
Author(s):  
Andrew D. Newman ◽  
D. Robert Brown ◽  
Prem Siril ◽  
Adam F. Lee ◽  
Karen Wilson
Keyword(s):  
Solid Acid ◽  
Solid Acid Catalysts ◽  
High Dispersion ◽  
Acid Catalysts ◽  
Structural Studies

A review on high catalytic efficiency of solid acid catalysts for lignin valorization

2020 ◽  
Vol 298 ◽  
pp. 122432 ◽  
Author(s):  
Weixiang Guan ◽  
Chi-Wing Tsang ◽  
Carol Sze Ki Lin ◽  
Christophe Len ◽  
Haoquan Hu ◽  
...  
Keyword(s):  
Solid Acid ◽  
Catalytic Efficiency ◽  
Solid Acid Catalysts ◽  
Acid Catalysts ◽  
Lignin Valorization

scholarly journals Niobium phosphotungstates: excellent solid acid catalysts for the dehydration of fructose to 5-hydroxymethylfurfural under mild conditions

RSC Advances ◽  
2018 ◽  
Vol 8 (57) ◽  
pp. 32423-32433 ◽  
Author(s):  
Guo Qiu ◽  
Xincheng Wang ◽  
Chongpin Huang ◽  
Yingxia Li ◽  
Biaohua Chen
Keyword(s):  
Heterogeneous Catalyst ◽  
Solid Acid ◽  
Solid Acid Catalysts ◽  
Acid Catalysts ◽  
Mild Conditions

A 5-HMF yield of 96.7% was obtained over an excellent heterogeneous catalyst NbPW-06 in DMSO at 80 °C.

Effects of Ultrasound Irradiation on Synthesis of Solid Acid Catalysts

2016 ◽  
Vol 701 ◽  
pp. 67-72 ◽  
Author(s):  
Mariam Ameen ◽  
Mohammad Tazli Azizan ◽  
Suzana Yusup ◽  
Anita Ramli ◽  
Madiha Yasir ◽  
...  
Keyword(s):  
Surface Area ◽  
Solid Acid ◽  
High Surface ◽  
High Surface Area ◽  
Ultrasound Irradiation ◽  
Solid Acid Catalysts ◽  
Acid Catalysts ◽  
Impregnation Method ◽  
Wet Impregnation ◽  
Wet Impregnation Method

The studies based on morphological characterization to assess the effects of ultrasound irradiation on synthesis of solid acid catalysts. Three sets of catalyst formulation were synthesized by both wet impregnation method and ultrasound assisted methods with different wt. % of Ni loading on γ-Al2O3. The XRD, BET, TEM and FESEM techniques were used to characterize the nano-particles. Physicochemical characterization revealed that the synthesized catalysts particles using ultrasound irradiation were in nano size range (1-24.5 nm) with equal dispersion of metal oxide, high surface area with increase of metal loading and high phase purity than the catalysts synthesized conventional method. These catalysts were also found in various crystal structures like cubic, monoclinic and tetrahedral. The use of ultrasound irradiation has great significance over the wet impregnation method in relation to the rate of synthesis of nanocatalysts. The high surface area, high thermal stability and small particle size (up to 1 nm) are the basic elements for high activity of solid acid catalysts in hydrocracking and hydrodeoxygenation of various feedstock in petroleum industries.

Experimental Study on Cellulose Hydrolysis Using Active Carbon-Based and Carbon Nanotube-Based Solid Acid Catalysts

2014 ◽  
Vol 953-954 ◽  
pp. 178-182 ◽  
Author(s):  
Yun Liu ◽  
Zong Ming Zheng ◽  
Jin Qi Zhu
Keyword(s):  
Solid Acid ◽  
Catalytic Efficiency ◽  
Cellulose Hydrolysis ◽  
Solid Acid Catalysts ◽  
Acid Catalysts ◽  
Hydrolysis Of Cellulose ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Hydrolysis Of ◽  
Carbon Based

Three kinds of carbon-based solid acid catalysts were prepared to hydrolyze cellulose with activated carbon (AC) and multi-walled carbon nanotubes (MWCNTs) as the carrier. The prepared solid acid catalysts were characterized by BET, SEM, XRD, FTIR and TG analysis. The catalytic activities of these prepared solid acid catalysts for heterogeneously catalyzed hydrolysis of microcrystalline cellulose were further investigated. The catalysts bearing hydroxyl, carboxyl and sulfonic groups is thermally stable. Due to the amorphous multi-layered structure and the large number of defected structure, AC-based solid acid bears more acid groups than the MWCNTs-based catalyst. which hence showing higher activity for the catalytic hydrolysis of cellulose. AC-based solid acid exihibited two-fold higher catalytic efficiency than that of the MWCNTs-based solid acid catalysts.

Green synthesis of bisphenol F over 12-phosphotungstic acid supported on acid-activated palygorskite

RSC Advances ◽  
2015 ◽  
Vol 5 (77) ◽  
pp. 62394-62401 ◽  
Author(s):  
Ran Liu ◽  
Xiaozhen Niu ◽  
Xinnian Xia ◽  
Zebing Zeng ◽  
Guozhong Zhang ◽  
...  
Keyword(s):  
Green Synthesis ◽  
Solid Acid ◽  
Phosphotungstic Acid ◽  
Solid Acid Catalysts ◽  
Acid Catalysts ◽  
Bisphenol F ◽  
Mild Conditions

Hydroxyalkylation of phenol to bisphenol F under mild conditions over various solid acid catalysts.

Preparation of Strong Acid Catalysts by Sulfate Treatment of Calcined Boehmite

1992 ◽  
Vol 57 (11) ◽  
pp. 2241-2247 ◽  
Author(s):  
Tomáš Hochmann ◽  
Karel Setínek
Keyword(s):  
Catalytic Activity ◽  
Surface Area ◽  
Aluminum Sulfate ◽  
Solid Acid ◽  
Strong Acid ◽  
Acid Strength ◽  
Solid Acid Catalysts ◽  
Acid Catalysts ◽  
Preparation Methods ◽  
Indicator Method

Solid acid catalysts with acid strength of -14.52 < H0 < -8.2 were prepared by sulfate treatment of the samples of boehmite calcined at 105-800 °C. Two preparation methods were used: impregnation of the calcined boehmite with 3.5 M H2SO4 or mixing of the boehmite samples with anhydrous aluminum sulfate, in both cases followed by calcination in nitrogen at 650 °C. The catalysts were characterized by measurements of surface area, adsorption of pyridine and benzene, acid strength measurements by the indicator method and by catalytic activity tests in the isomerization of cyclohexene, p-xylene and n-hexane. Properties of the catalysts prepared by both methods were comparable.

scholarly journals Metal–Organic Framework-Based Solid Acid Materials for Biomass Upgrade

2021 ◽  
Author(s):  
Yutian Qin ◽  
Jun Guo ◽  
Meiting Zhao
Keyword(s):  
High Efficiency ◽  
Solid Acid ◽  
Metal Organic Framework ◽  
Acid Sites ◽  
Solid Acid Catalysts ◽  
Future Research ◽  
Acid Catalysts ◽  
Metal Organic ◽  
Biomass Transformation ◽  
Organic Framework

AbstractBiomass is a green and producible source of energy and chemicals. Hence, developing high-efficiency catalysts for biomass utilization and transformation is urgently demanded. Metal–organic framework (MOF)-based solid acid materials have been considered as promising catalysts in biomass transformation. In this review, we first introduce the genre of Lewis acid and Brønsted acid sites commonly generated in MOFs or MOF-based composites. Then, the methods for the generation and adjustment of corresponding acid sites are overviewed. Next, the catalytic applications of MOF-based solid acid materials in various biomass transformation reactions are summarized and discussed. Furthermore, based on our personal insights, the challenges and outlook on the future development of MOF-based solid acid catalysts are provided. We hope that this review will provide an instructive roadmap for future research on MOFs and MOF-based composites for biomass transformation.

scholarly journals Nonthermal Plasma Induced Fabrication of Solid Acid Catalysts for Glycerol Dehydration to Acrolein

Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 391
Author(s):  
Lu Liu ◽  
Xiaofei Philip Ye
Keyword(s):  
Solid Acid ◽  
Nonthermal Plasma ◽  
Temperature Programmed Desorption ◽  
Argon Atmosphere ◽  
Solid Acid Catalysts ◽  
Acid Catalysts ◽  
Pyridine Adsorption ◽  
X Ray ◽  
Glycerol Dehydration ◽  
Temperature Programmed

The feasibility of fabricating better solid acid catalysts using nonthermal plasma (NTP) technology for biobased acrolein production is demonstrated. NTP discharge exposure was integrated in catalyst fabrication in air or argon atmosphere. The fabricated catalysts were characterized by Brunauer–Emmett–Teller surface area analysis, temperature-programmed desorption of ammonia, X-ray powder diffraction and Fourier-transform infrared spectroscopy of pyridine adsorption, in comparison to regularly prepared catalysts as a control. Further, kinetic results collected via glycerol dehydration experiments were compared, and improvement in acrolein selectivity was displayed when the catalyst was fabricated in the argon NTP, but not in the air NTP. Possible mechanisms for the improvement were also discussed.

Sign in / Sign up

Export Citation Format

Share Document