Chromium oxide zirconia solid acid catalyst for n-pentane isomerization

New catalyst based on zirconia (ZrO2) supported by chromium oxide (CrO3) for isomerization of n-pentane was studied. CrO3-ZrO2 was prepared with chromium nitrate by the titration and sol-gel technique. The physical properties of the catalysts were characterized by XRD, BET surface area analyzer, and TEM. The acidity and structure of catalysts were determined by pyridine and lutidine preadsorbed FTIR spectroscopy. The isomerization of n-pentane was carried out at 523 K under hydrogen stream. CrO3-ZrO2 shows the differences in terms of physical properties where the introduction CrO3 partially eliminated the monoclinic phase of ZrO2 and developed new peaks assigned to tetragonal phase of ZrO2. CrO3-ZrO2 also shows a higher specific surface area where it increases in the pore volume of the catalyst compare to its parent zirconia. The IR results indicated that CrO3-ZrO2 catalyst have strong Lewis and weak Brønsted acid sites. The conversion of n-pentane for CrO3-ZrO2 was 32% respectively, while the selectivity to iso-pentane was 100%. ________________________________________GRAPHICAL ABSTRACT

Download Full-text

Synthesis of 2,3-dihydroquinazolin-4(1H)-ones catalyzed by Perchlorated Zirconia (HClO4/ZrO2) nanoparticles as a novel solid acid catalyst

Nanoscience and Nanotechnology ◽

10.18063/nn.v0i0.449 ◽

2018 ◽

Vol 2 (2) ◽

Author(s):

Seyed Yousef Mosavian

Keyword(s):

Solid Acid ◽

Condensation Reaction ◽

Solid Acid Catalyst ◽

Sol Gel ◽

Acid Catalyst ◽

Catalytic Performance ◽

Acid Sites ◽

Zro2 Nanoparticles ◽

Calcination Temperatures ◽

Aldehydes And Ketones

Zirconia was synthesized in nanosize by sol-gel method and perchlorated zirconia (HClO4/ZrO2) with various calcination temperatures were prepared and characterized by XRD, FTIR and SEM techniques. The catalyst acidity characters, including the acidicstrength and the total number of acid sites were determined by potentiometric titration. The catalytic performance experiments show that the HClO4/ZrO2 with calcination temperature of 300 °C has the best catalytic activity. 2,3-Dihydroquinazolin-4(1H)-ones wereprepared in good to excellent yields via condensation reaction of oaminobenzamide and various types of aldehydes and ketones in the presence of HClO4/ZrO2 nanoparticles as an efficient solid acid catalyst. The catalyst is reusable with moderate loss in activity.

Download Full-text

Synthesis, Characterization and Catalytic Performance ofH3SiW12O40/SiO2Prepared by Sol-Gel Technique

Journal of Nanotechnology ◽

10.1155/2011/507692 ◽

2011 ◽

Vol 2011 ◽

pp. 1-6 ◽

Cited By ~ 7

Author(s):

W. N. R. W. Isahak ◽

M. Ismail ◽

N. M. Nordin ◽

J. M. Jahim ◽

M. A. Yarmo

Keyword(s):

Heteropoly Acid ◽

Solid Acid ◽

Solid Acid Catalyst ◽

Sol Gel ◽

Acid Catalyst ◽

Catalytic Performance ◽

Environmentally Benign ◽

Esterification Reaction ◽

Silicotungstic Acid ◽

Gel Technique

The purpose of this work is to study the synthesis, characterization, and catalytic performance of two types of solid heteropoly acid catalysts, namely, silicotungstic acid bulk (STAB) and STA-silica sol-gel (STA-SG) compared with sulfuric acid. From the XPS analyses, there was a significant formation of W-O-Si, W-O-W, and Si-O-Si bonding in STA-SG compared to that in STAB. The main spectra of O1s (90.74%, 531.5 eV) followed by other O1s peak (9.26%, 532.8 eV) were due to the presence of W-O-W and W-O-Si bonds, respectively. The STA-SG catalyst was found to be the more environmentally benign solid acid catalyst for the esterification reaction between oleic acid and glycerol due to its lower toxicity supported by silica via sol-gel technique. In addition, the ease of separation for STA-SG catalyst was attributed to its insoluble state in the product phase. The esterification products were then analysed by FTIR and HPLC. Both the H2SO4and the STAB gave high conversion of 100% and 98% but at a lower selectivity of GME with 81.6% and 89.9%, respectively. On the contrary, the STA-SG enabled a conversion of 94% but with a significantly higher GME selectivity of 95%, rendering it the more efficient solid acid catalyst.

Download Full-text

Tungstophosphoric Acid Entrapped on Mesoporous Silica via Sol Gel Technique

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.11-12.69 ◽

2006 ◽

Vol 11-12 ◽

pp. 69-72

Author(s):

Joon Ching Juan ◽

Yarmo Mohd Ambar ◽

Jing Chang Zhang

Keyword(s):

Mesoporous Silica ◽

Solid Acid ◽

Solid Acid Catalyst ◽

Sol Gel ◽

Chemical Properties ◽

Acid Catalyst ◽

Tungstophosphoric Acid ◽

Esterification Reaction ◽

Heterogeneous Acid Catalyst ◽

Gel Technique

The heterogeneous 12-tungstophosphoric acid (HPW) catalyst is becoming important in industrial processes for example in esterification reaction. A novel solid acid catalyst of HPW entrapped on mesoporous silica was synthesized by sol gel technique. Neutral template dodecylamine was introduced to obtain mesopores structure catalyst. The physical and chemical properties of the catalyst were characterized by XRD, nitrogen sorption and FTIR. In conclusion, this new type of mesoporous solid acid catalyst is a very promising heterogeneous acid catalyst for esterification reaction involving bulky molecules such as fatty acid.

Download Full-text

Preparation of a novel solid acid catalyst with Lewis and Br{\o}nsted acid sites and its application in acetalization

TURKISH JOURNAL OF CHEMISTRY ◽

10.3906/kim-1302-70 ◽

2014 ◽

Vol 38 ◽

pp. 157-163 ◽

Cited By ~ 5

Author(s):

Yijun DU ◽

Linjun SHAO ◽

Lingyan LUO ◽

Si SHI ◽

Chenze QI

Keyword(s):

Solid Acid ◽

Solid Acid Catalyst ◽

Acid Catalyst ◽

Acid Sites

Download Full-text

Sulfonated Mesoporous Silica-Carbon Composite Derived from a Silicate-Polyethylene Glycol Gel and Its Application as Solid Acid Catalysts

BULLETIN OF CHEMICAL REACTION ENGINEERING AND CATALYSIS ◽

10.9767/bcrec.17.1.11795.13-21 ◽

2021 ◽

Vol 17 (1) ◽

pp. 13-21

Author(s):

Shofiyya Julaika ◽

Agus Farid Fadli ◽

Widiyastuti Widiyastuti ◽

Heru Setyawan

Keyword(s):

Acetic Acid ◽

Polyethylene Glycol ◽

Mesoporous Silica ◽

Surface Area ◽

Sodium Silicate ◽

Solid Acid ◽

Solid Acid Catalyst ◽

Acid Catalyst ◽

Carbon Composite ◽

Esterification Reaction

Solid acid catalyst is a promising alternative to the counterpart homogeneous acid for esterification reaction from the viewpoint of reusability and environmental concerns. This work aims to develop sulfonated mesoporous silica-carbon composite as solid acid catalyst for the esterification. The catalyst was synthesized from sodium silicate as the silica precursor and polyethylene glycol (PEG) as both carbon precursor and template via a sol-gel route in an aqueous system. Then, it was carbonized to produce mesoporous silica-carbon composite. Using the proposed method, the surface area of the silica-carbon composite could reach as high as 1074.21 m2/g. Although the surface area decreased to 614.02 m²/g when it was functionalized with sulfonate groups, the composite had a high ionic capacity of 5.3 mEq/g and exhibited high catalytic activity for esterification reaction of acetic acid with ethanol. At a reaction temperature of 80 °C, the acetic acid conversion reached 76.55% in 4 h. In addition, the catalyst had good reusability, which can be comparable with the commercial catalyst Foltrol F-007. It appears that the sulfonated silica-carbon composite prepared from sodium silicate using PEG as the carbon source a promising candidate as catalyst for esterification and the related area. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Download Full-text

Sintesis silika tersulfonasi dari waterglass dengan templat PEG sebagai katalis asam padat dalam pembuatan pelumas dari minyak nabati Synthesis of sulfonated silica from waterglass with PEG template as solid acid catalyst in the production of lubricant from vegetable oil

E-Journal Menara Perkebunan ◽

10.22302/iribb.jur.mp.v81i2.44 ◽

2016 ◽

Vol 81 (2) ◽

Author(s):

Sri WAHYUNI ◽

Heru SETYAWA

Keyword(s):

Fourier Transform ◽

Surface Area ◽

Solid Acid ◽

Solid Acid Catalyst ◽

Base Material ◽

Acid Catalyst ◽

Catalyst System ◽

Solid Catalyst ◽

Template Process ◽

Homogeneous Acid

AbstractThe use of a catalyst in the manufacture of lubricantscome through many developments, from a homogeneousbase catalysts, homogeneous acid catalyst to hetero-geneous solid catalyst system (heterogenous catalyst). Oneexample of heterogeneous catalyst base material is silica.The purpose of this research was to study the graftingmethod of sulfonic group on silica from waterglass withPEG (polyethylene glycol) template as solid acid catalystand to analyze the effect of PEG concentration on ioniccapacity. Silica sol was produced by addition of PEG andHCl into waterglass. The PEG template was separated bytwo different methods; solvothermal extraction andcalcinations process. The following step was graftingprocess of the sulfonate into the silica powder, and dryingthe silica sulfonate in certain temperature. The driedsulfonated silica particles were characterized for theirpore size by BET method, the functional group by FTIR(Fourier Transform Infra Red) test, and the ionic capacityby titrimetry analysis. The result showed that the separatedPEG template process with calcinations method gave abetter result than the solvothermal extraction methodbased on the amount of PEG that disappear. While fromBET result showed that the calcinations process producedsmaller surface area pore than the extraction solvothermalprocess. The effect of the concentration of PEG template,showed that the surface area mostly decreased with theaddition of the PEG template concentration and increasedagain at 0.0178 g/mL. The biggest ionic capacity at 12,603mmol eq/g silica was obtained from solvothermal method.AbstrakPenggunaan katalis dalam pembuatan pelumas me-ngalami banyak perkembangan, dari katalis homogenbasa, katalis homogen asam hingga dikembangkanpenggunaan katalis padat sistem heterogen (heterogenouscatalyst). Salah satu contoh bahan dasar dari katalisheterogen ini adalah silika. Penelitian ini bertujuan untukmempelajari teknik pencangkokan gugus sulfonat pada silika dari waterglass dengan templat PEG (polyethyleneglycol) sebagai katalis asam padat dan menganalisapengaruh konsentrasi templat terhadap kapasitas ion. Solsilika dibuat dengan menambahkan PEG dan HCl kedalam waterglass. Templat PEG dihilangkan dengan duacara yang berbeda yaitu ekstraksi solvothermal dankalsinasi. Proses selanjutnya adalah pencangkokansulfonat pada serbuk silica dan silika tersulfonasi padasuhu tertentu. Partikel silika tersulfonasi yang telah keringdikarakterisasi ukuran porinya dengan metode BET,gugus fungsi dengan uji FTIR (Fourier Transform InfraRed), dan kapasitas ionik dengan analisis titrimetri. Hasilpenelitian menunjukkan bahwa metode kalsinasi ternyatadapat menghilangkan senyawa PEG lebih baik di-bandingkan dengan metode ekstraksi solvothermal, tetapiberdasarkan hasil BET, penghilangan templat melaluiproses kalsinasi menghasilkan luas permukaan yang lebihkecil jika dibandingkan dengan kondisi sebelum templatdihilangkan, sedangkan ekstraksi solvothermal meng-hasilkan luas permukaan silika yang lebih besar. Untukpengaruh konsentrasi templat PEG, didapatkan hasilbahwa luas permukaan partikel silika cenderung turundengan penambahan templat dan naik kembali padakonsentrasi 0,0178 g/mL. Kapasitas ionik terbesar di-dapat pada silika dengan metode solvothermal yaitusebesar 12,603 mmol/g silika.

Download Full-text

Synthesis of Some Aromatic and Aliphatic Esters Using WO3/ZrO2 Solid Acid Catalyst under Solvent Free Conditions

Asian Journal of Chemistry ◽

10.14233/ajchem.2020.22683 ◽

2020 ◽

Vol 32 (9) ◽

pp. 2153-2157

Author(s):

VIJAYA CHARAN GUGULOTH ◽

SATYANARAYANA BATTU

Keyword(s):

Surface Area ◽

Tetragonal Phase ◽

Solid Acid ◽

Solid Acid Catalyst ◽

Acid Catalyst ◽

Esterification Reaction ◽

Impregnation Method ◽

Simple Method ◽

Solvent Free Conditions ◽

Zro2 Catalyst

A simple method is delineated for the synthesis of substituted ester products in superior yields by esterification reaction under solvent unbound condition using tungsten upgraded ZrO2 solid acid catalyst at 353 K. The WO3/ZrO2 catalyst has been prepared by using impregnation method followed by calcination at 923 K over a period of 6 h in air atmosphere. SEM, XRD, FTIR, and BET surface area techniques were used to categorize this catalyst. Zirconia has both acidic and basic possessions which can be changed by incorporating suitable promoter atom like tungsten which in turn increases the surface area thereby enhancing the surface acidity. Impregnation of W6+ ions exhibits a strong influence on phase modification of zirconia from thermodynamically solid monoclinic to metastable tetragonal phase. Amalgamation of promoter W6+ will stabilize tetragonal phase which is active in catalyzing reactions. In esterification reaction WO3/ZrO2 catalyst was found to be stable, efficient and environmental friendly, effortlessly recovered by filtration, excellent yield of product and can be reusable efficiently.

Download Full-text

Acid Properties of GO and Reduced GO as Determined by Microcalorimetry, FTIR, and Kinetics of Cellulose Hydrolysis-Hydrogenolysis

Catalysts ◽

10.3390/catal10121393 ◽

2020 ◽

Vol 10 (12) ◽

pp. 1393

Author(s):

Van Chuc Nguyen ◽

Sarah Kheireddine ◽

Amar Dandach ◽

Marion Eternot ◽

Thi Thu Ha Vu ◽

...

Keyword(s):

Graphene Oxide ◽

Solid Acid ◽

Solid Acid Catalyst ◽

High Mobility ◽

Acid Catalyst ◽

Strong Acid ◽

Cellulose Hydrolysis ◽

Acid Sites ◽

Pyridine Adsorption ◽

Nh3 Adsorption

Graphene oxide addresses increasing interests as a solid acid catalyst working in water for carbohydrate conversion. If there is a general agreement to correlate its unique catalytic performances to its ability to adsorb sugars, the origin of its acidity remains controversial. In this article, we study the acid strength of graphene oxide (GO) prepared by modified Hummers method and that of reduced GO by calorimetry of NH3 adsorption and by FTIR of pyridine adsorption. Very strong acid sites are detected on GO by calorimetry, while reduced graphene oxide (reGO) is not very acidic. The FTIR of pyridine adsorption shows the prevailing presence of Br∅nsted acid sites and a unique feature, the presence of pyridine coordinated by hydrogen bonds. This exceptionally strong Br∅nsted acidity is tentatively explained by the presence of graphene domains decorated by hydroxyl, carboxylic, or sulfonated groups within the GO sheet, resulting in a high mobility of the negative charges which makes the proton free and explains its strong acidity. Accordingly, only GO is active and selective for native cellulose hydrolysis, leading to 27% yield in glucose. Finally, we show that sugar alcohols cannot be formed directly from cellulose using GO combined with Pt/re-GO under hydrogen, explained by the reduction of oxygenated functions of GO. The instability of the functional groups of GO in a reducing atmosphere is the weak point of this peculiar solid acid.

Download Full-text