Application of hydrothermally produced TiO2 nanotubes in photocatalytic esterification of oleic acid

Manique, Márcia Cardoso; Silva, Aline Posteral; Alves, Annelise Kopp; Bergmann, Carlos Pérez

doi:10.1016/j.mseb.2016.01.001

Cited by 33 publications

(30 citation statements)

References 36 publications

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“…Figure 5 showed that the Lewis acid center (Ti 4+ ) forms an intermediate complex with the carbonyl oxygen of CA. 34 Consequently, the intermediate complex eliminates the water while forming the desired product (GMC). 33 Subsequently, the Brønsted acid site (H + ) gets linked with the tetrahedral complex followed by the subsequent release of Ti 4+ ions.…”

Section: Reaction Mechanismmentioning

confidence: 99%

“…33 Subsequently, the Brønsted acid site (H + ) gets linked with the tetrahedral complex followed by the subsequent release of Ti 4+ ions. 34 Consequently, the intermediate complex eliminates the water while forming the desired product (GMC). The ester and the by-product water were desorbed and diffused out of catalyst sites, and water was eventually adsorbed by desiccants while GMC stayed in the bulk phase.…”

Section: Reaction Mechanismmentioning

confidence: 99%

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Quartz halogen‐ultrasonication integrated rotating reactor for efficient photocatalytic‐thermocatalytic synthesis of glyceryl monocaprin: Kinetics of heterogeneous esterification

Karan

Mukhopadhyay

Chakraborty

2019

Asia-Pacific J Chem Eng

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A pioneering intensification protocol for glyceryl monocaprin (GMC) synthesis deploying coactive electromagnetic energies,viz. quartz halogen radiation (QHR) and ultrasonication (US) is explored. Concurrently, Amberlyst 15 (A15) and nano-TiO 2 P25 (NT-P25) were applied to achieve capric acid (CA) conversion of 97% ± 0.5%, employing the integrated QHR-US energized rotating reactor (QHRUERR), which was 7.5% ± 0.5% higher than QH energized rotating reactor (QHERR) and 20% ± 1% greater compared to an ultrasonically energized rotating reactor (USERR). Optimal factors, viz., 0.35:1 CA:glycerol mole ratio, 343K temperature, 0.67:1 A15:P25(wt./wt.) dose, resulted maximum GMC selectivity (95% ± 0.3%). Langmuir-Hinshelwood model (R 2 = .99) could best represent the esterification kinetics in QHRUERR under optimal condition. Significantly, reaction activation energy was found minimum in QHRUERR (9.63 kJ/mol) compared with a rotating reactor equipped either with QHR (27.5 kJ/mol) or the US (32.74 kJ/mol), thus implying promising synergy and energy efficiency of QHRUERR. Ultraviolet-visible diffuse reflectance spectra and photoluminescence analyses exhibited the photoactivity of ATO (A15 : NT-P25=0.67: 1 w/w) catalyst possessing lower band gap energy (2.98 eV). The optimal product GMC demonstrated appreciable food preservative attributes toward Aspergillus Niger food pathogen. An energy-efficient and sustainable reactor could, thus, be explored in this study for proficient green synthesis of valuable food preservatives.

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Section: Reaction Mechanismmentioning

confidence: 99%

Section: Reaction Mechanismmentioning

confidence: 99%

Quartz halogen‐ultrasonication integrated rotating reactor for efficient photocatalytic‐thermocatalytic synthesis of glyceryl monocaprin: Kinetics of heterogeneous esterification

Karan

Mukhopadhyay

Chakraborty

2019

Asia-Pacific J Chem Eng

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“…Kemiri Sunan (Reutealis trisperma) oil has a high potential to be a feedstock in producing methyl esters [1,2], which are the main components of eco-green surfactant (methyl ester sulfonate-MES) [3] and bio-fuel (fatty acid methyl esther-FAME) [4]. Fatty acid methyl e s t e r ( R C O O R ' ) h a s a d v a n t a g e o u s characteristics, such as: non-toxic, sulphur free, renewable, and biodegradable [5]. It can be synthesized from vegetable oil including palm, soybean, rapeseed, sunflower, etc.…”

Section: Introductionmentioning

confidence: 99%

“…Photocatalytic esterification has been studied by Corro et al [17,18], who used ZnO/SiO2 for converting the FFA content of Jatropa curcas and Cr/SiO2 for waste frying oil. Manique et al [5] studied photocatalytic esterification of oleic acid using nanotube TiO2 and Verma et al [19] studied that of acetic acid using activated TiO2. The catalysts are highly active for the esterification and can be reused ten times.…”

Section: Introductionmentioning

confidence: 99%

Simultaneous Photocatalytic Esterification and Addition Reaction of Fatty Acids in Kemiri Sunan (Reutealis trisperma sp.) Oil over CuO/TiO2 Catalyst - A Novel Approach

Redjeki

Sukirno

Slamet

2021

Bull. Chem. React. Eng. Catal.

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A novel approach, namely photocatalytic esterification and addition reaction of unsaturated fatty acids using CuO/TiO2 catalyst has been investigated in kemiri sunan oil. The objectives of this study are to reduce the free fatty acid (FFA) content by using catalyst CuO/TiO2, characterization of the catalyst and the operation condition of reaction. The CuO/TiO2 catalyst was synthesized by the impregnation of TiO2 P25 powder with copper nitrate solution as a precursor and followed by calcination. The field emission scanning electron microscopy (FESEM), Energy Dispersive X-ray (EDX), X-ray Diffraction (XRD), and Transmission electron microscopes (TEM) result showed that copper oxide was highly dispersed on the TiO2 surface. The X-ray Photoelectron Spectroscopy (XPS) result showed that Cu is in the state of CuO (Cu2+), while Ti is in Ti4+ ( TiO2). The bandgap energy of CuO/TiO2 was smaller than TiO2 P25. It was found that the reactions conducted in the presence of CuO/TiO2 in a photoreactor under UV irradiation can perform esterification and addition reaction of the FFA, simultaneously. The optimum reduction of the FFA was under condition of 4% loading CuO/TiO2, 4 hours reaction time, 30:1 (mole/mole) methanol to oil ratio, 5% (w/w) catalyst amount. The conversion of FFA was at around 59%. The Gas Chromatography—Mass Spectrometry (GC-MS) results showed that the addition reaction of -eleostearic acid simultaneously occured at 100% conversion. Although the photocatalyst selectivity in FFA reduction was relatively low, but double bond reduction of -eleostearic acid (C18:3) was very high. The reduction of multiple double bond is considered as positive poin to improve the oxidative stability of the product. The simultaneous esterification and addition reactions mechanism has been proposed. 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).

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“…Sodium titanates are promising materials that have been studied for biodiesel production. In this context, 97% conversion efficiency for biodiesel has been obtained via transesterification of triglycerides and up to 54% via photocatalytic esterification of fatty acids [7,8]. Potassium-based titanates are also very attractive since close to 100% biodiesel production conversions have been reported [9,10].…”

Section: Introductionmentioning

confidence: 99%

The Roles of the Structure and Basic Sites of Sodium Titanates on Transesterification Reactions to Obtain Biodiesel

et al. 2019

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Sodium titanates were evaluated as heterogeneous catalysts for biodiesel production. Materials were prepared using an experimental design considering NaOH and TiO2 concentrations and hydrothermal and calcination temperatures as input variables. Materials characterization was carried out by DRX-Rietveld refinement, CO2-TPD, and XPS. Statistical analysis of the experimental results indicates that the calcination temperature is the most influential factor in the formation of sodium titanates with high catalytic performance in transesterification reactions. Further analysis of the oil-to-biodiesel conversion revealed that the catalytic activity of sodium titanates is directly correlated to the catalyst associated species and to the density of medium-strong basic sites on the surface of the material, obtaining up to 95% conversion to biodiesel at 60 °C using 3.6% weight catalyst with respect to oil.

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Application of hydrothermally produced TiO2 nanotubes in photocatalytic esterification of oleic acid

Cited by 33 publications

References 36 publications

Quartz halogen‐ultrasonication integrated rotating reactor for efficient photocatalytic‐thermocatalytic synthesis of glyceryl monocaprin: Kinetics of heterogeneous esterification

Quartz halogen‐ultrasonication integrated rotating reactor for efficient photocatalytic‐thermocatalytic synthesis of glyceryl monocaprin: Kinetics of heterogeneous esterification

Simultaneous Photocatalytic Esterification and Addition Reaction of Fatty Acids in Kemiri Sunan (Reutealis trisperma sp.) Oil over CuO/TiO2 Catalyst - A Novel Approach

The Roles of the Structure and Basic Sites of Sodium Titanates on Transesterification Reactions to Obtain Biodiesel

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