KMITL

Permanent URI for this communityhttps://dspace.kmitl.ac.th/handle/123456789/1

Browse

Search Results

Now showing 1 - 4 of 4

Some of the metrics are blocked by your
consent settings
Novel Waste-Derived Cu–Zn/Zeolite A Catalyst for Ethanol Dehydrogenation to Highly Selective Acetaldehyde
(2026-05-05)
Sukchit, Darunee
;
Prajuabsuk, Malee
;
Lumlong, Saisamorn
;
Inntam, Chan
;
Pakamwong, Bongkochawan
A sustainable and highly selective catalyst for ethanol dehydrogenation, Cu–Zn/Zeolite A derived from sugarcane bagasse ash (ZA-SBA), was developed using silica-rich agricultural waste as a low-cost precursor for zeolite A synthesis. Zeolite A was crystallized via hydrothermal treatment of SBA-derived precursors and subsequently modified with 15 wt % Cu and 15 wt % Zn using the incipient wetness impregnation method. Comprehensive characterization (XRF, XRD, SEM-EDX, TEM, FTIR, BET, XPS, NH<inf>3</inf>-TPD, NH<inf>3</inf>–FTIR, and CO<inf>2</inf>-TPD) confirmed the successful formation of zeolite A with enhanced crystallinity, surface area, and basicity. CO<inf>2</inf>-TPD analysis revealed a notable increase in medium-to-strong basic sites (32.76 μmol of CO<inf>2</inf> /g), over three times higher than that of the unmodified support. These basic sites, in synergy with highly dispersed Cu and Zn species, facilitated ethanol activation and hydride elimination while suppressing dehydration and etherification side reactions. In gas-phase ethanol dehydrogenation, the Cu–Zn/ZA-SBA catalyst exhibited outstanding performance, achieving 56.5% ethanol conversion and 99.7% selectivity toward acetaldehyde at 350 °C. This superior activity is attributed to the cooperative interaction between Cu and Zn species and the tailored acid–base surface properties of the SBA-derived zeolite A support. The present work demonstrates the valorization of sugarcane bagasse ash into functional zeolitic materials, providing a green, low-cost, and efficient strategy for developing sustainable catalysts for bioethanol upgrading into value-added acetaldehyde.
Some of the metrics are blocked by your
consent settings
Synthesis and Characterization of Zeolite A from Industrial Fly Ash as a Green, Cost-Effective Cd2+ and Pb2+ Adsorbent for Wastewater Applications
(2025-02-18)
Sukchit, Darunee
;
Prajuabsuk, Malee
;
Lumlong, Saisamorn
;
Inntam, Chan
;
Punkvang, Auradee
According to the large amount of fly ash waste generated from the use of lignite coal as the primary fuel for electricity generation in the Mae Moh district of Lampang province, Thailand, efforts have been made in waste management to reduce and repurpose this industrial byproduct. In this study, lignite coal fly ash was used to synthesize zeolite A adsorbents for the treatment of wastewater contaminated with heavy metals. Characterization of the synthesized zeolite using XRD, XRF, BET, and SEM methods confirmed that it is zeolite A, with a calculated Si/Al molar ratio of approximately 1.19, closely matching the theoretical ratio of zeolite A. This zeolite A exhibited a high crystalline phase and a mesoporous structure, having a specific surface area of 37.10 m2/g and a total pore volume of 0.06 cm3/g. The performance of this zeolite A was evaluated for the adsorption of Cd2+ and Pb2+ in prepared solutions. The removal efficiencies of zeolite A for Cd2+ and Pb2+ were 99.65% ± 0.1% and 93.90% ± 0.5%, with maximum adsorption capacities of 17.3 ± 0.6 and 8.8 ± 0.1 mg/g, respectively. Additionally, zeolite A demonstrated reusability for the adsorption of Cd2+ and Pb2+, maintaining a removal efficiency of 80.52% ± 0.1% for Cd2+ over five reuse cycles, and 96.83% ± 0.7% for Pb2+ over one reuse cycle. The adsorption of Cd2+ and Pb2+ by zeolite A followed the Langmuir isotherm model and pseudo-second-order kinetic model. Moreover, the adsorption of Cd2+ and Pb2+ by zeolite A was found to be a spontaneous, endothermic process, as evidenced by increasingly negative Gibbs free energy change (ΔG°) values with rising temperature. Density functional theory (DFT) calculations were also performed to investigate the binding of Cd2+ and Pb2+ ions to zeolite A, providing insight into why Cd2+ exhibits a slightly higher affinity than Pb2+. The results showed that Cd2+ ions have a marginally greater affinity for zeolite A compared to Pb2+ (−85.72 vs −85.39 kcal/mol), which aligns with experimental findings. This study offers an alternative approach for reducing industrial waste by repurposing it for valuable applications, contributing to sustainable waste management practices that align with the principles of the bio-circular-green economy.
Some of the metrics are blocked by your
consent settings
Synthesis and cytotoxicity study of gold(III) porphyrin complexes and their derivative in breast cancer cells
(2021-12-01)
Phromsatit, Tossapon
;
Arpornmaeklong, Premjit
;
Shirosaki, Yuki
;
Teerawatananond, Thapong
;
Rabablert, Jundee
Gold(III) [Au(III)] complexes exhibit potential anticancer activities. A series of Au(III) porphyrin complexes containing different meso-substituent groups (phenyl, methoxyphenyl, butyloxyphenyl, octyloxyphenyl, and decyloxyphenyl) was synthesized. The synthesized compounds were characterized using mass spectrometry, infrared spectroscopy, UV–visible and fluorescence spectroscopy, and electron paramagnetic resonance spectroscopy. Moreover, the in vitro cytotoxicity of these Au(III) porphyrin complexes was investigated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide surrogate viability assay on an MCF7 human breast cancer cell line. The Au(III) complexes with 5,10,15,20-tetraphenylporphyrin (AuTPP) and 5,10,15,20-tetrakis(4-methyloxyphenyl)porphyrin (AuTOMPP) demonstrated high anticancer activity with IC<inf>50</inf> values against MCF7 cells at 4.30 and 25.35 µM, respectively. The toxicity of the Au(III) porphyrin complexes against the LLC-MK2 rhesus monkey kidney epithelial cell line, a representative normal cell line, was investigated. All the tested Au(III) porphyrin complexes were non-cytotoxic in LLC-MK2 cells. For AuTPP, more than 80% LLC-MK2 cell viability was observed at concentrations lower than 5 μM.
Some of the metrics are blocked by your
consent settings
Fractionation, antioxidant and inhibitory activity of Thai mango seed kernel extracts
(2018-01-01)
Namngam, Chaianun
;
Boonyuen, Supakorn
;
Pinsirodom, Praphan
Mango seed kernel extracts (MSKE) from Kaew and Choke-Anan mango cultivars were fractionated using Sephadex LH-20 column chromatography. Antioxidant activity and the inhibitory effects on tyrosinase, 5-lipoxygenase, hyaluronidase and α-glucosidase of MSKE fractions were evaluated. The key components of polyphenol, found in the most active fraction, were identified using LC-ESI-MS. Three major isolates were obtained from both cultivars of the MSKE with the absorbance being higher for Choke-Anan than Kaew. Fraction 3 of MSKE from both cultivars showed significantly (P ≤ 0.05) higher antioxidant activity and 5-lipoxygenase, hyaluronidase and α-glucosidase inhibitory activity with Choke-Anan more effective than Kaew. Six different polyphenols were found in fraction 3 of both cultivars. These were tri-o-galloyl-glucoside, tetra-o-galloyl-glucoside, maclurin tri-o-galloyl-glucoside, penta-o-galloyl-glucoside, hexa-o-galloyl-glucoside, and hepta-o-galloyl-glucoside. In the MSKE from Choke-Anan, hexa-o-galloyl-glucoside, and tetra-o-galloyl-glucoside were the two major components, whereas in the MSKE from Kaew tetra-o-galloyl-glucoside was the only major component. The results indicate that MSKE is a suitable by-product that could be utilised for adding value to the mango processing industry and could represent a valuable input into functional foods and pharmaceutical production.

KMITL

Browse

Filters

Settings

Sort By

Results per page

Search Results