Browsing by Author "Lin, Liang-Yi"

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A comparative investigation on the low-temperature catalytic oxidation of acetone over porous aluminosilicate-supported cerium oxides
(2015-03-15)
Lin, Liang-Yi
;
Wang, ChenYeh
;
Bai, Hsunling
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環境工程研究所
;
Institute of Environmental Engineering
The performance of cerium oxide supported on mesoporous aluminosilicate particles (Al-MSPs) with a nominal Ce and Al loading of 2.8 and 1.2 wt.%, respectively, was evaluated for the low-temperature oxidation of acetone. The influence of the preparation methods, including one-step aerosol-assisted self-assembly (AASA) method and post-synthetic wet impregnation method, was examined. The results showed that the surface area and pore diameter of Ce/Al-MSPs(50/25) prepared by AASA method were similar to those of Ce-Al-MSPs made via traditional impregnation method, while a better metallic dispersion of Ce and Al oxide species on Ce/Al-MSP5(50/25) was observed as compared to that of Ce-Al-MSPs. The catalytic performances of Ce/Al-MSPs(50/25) and Ce-Al-MSPs were compared with that of cerium-impregnated H-ZSM-5 (Ce-ZSM-5) zeolite catalyst. The activity of freshly made catalysts followed the order: Ce/Al-MSPs(50/25) > Ce-ZSM-5 > Ce-Al-MSPs. The superior catalytic behavior of the Ce/Al-MSPs(50/25) could be due to the combined effect of strong surface reducibility and high acid property. Although Ce-ZSM-5 and Ce-Al-MSPs presented high activity for acetone removal in the beginning, their activities quickly decreased due to the coking effect. In contrast, Ce/Al-MSP5(50/25) showed a good stability during a 24 h test at the reaction temperature of 150 degrees C. Both surface reducibility and acidity played crucial roles for their high catalytic performance and high stability at low temperatures. (C) 2014 Elsevier B.V. All rights reserved.
Aerosol processing of low-cost mesoporous silica spherical particles from photonic industrial waste powder for CO2 capture
(1970-01-01)
Lin, Liang-Yi
;
Bai, Hsunling
;
環境工程研究所
;
Institute of Environmental Engineering
"A novel mesoporous silica spherical particle, MSP (AS) was facilely prepared using photonic industrial waste powder as the silica source via salt-templated aerosol spray approach. As an alternative to expensive mesoporous silica materials in prior works, the obtained MSP (AS) possesses advantages of simple and rapid synthesis with low manufacturing costs. The characteristics of the MSP (AS) material were investigated by the XRD. N-2 adsorption-desorption measurement, SEM, TEM and TG/DTG analyses. The results clearly demonstrated the presence of mesoporous siliceous material with high specific surface area (585 m(2)/g), mesopore size (9.1 nm) as well as large pore volume (1.24 cm(3)/g). Furthermore, the MSP (AS) is evaluated as the support of adsorbent in terms of CO2 adsorption. It is observed that the amine-functionalized MSP (AS) adsorbent (TEPA-MSP (AS)) which possessed larger pore diameter and pore volume tends to have a higher adsorption capacity of 127 mg CO2/g adsorbent. This is superior to those of TEPA-SBA-15 (117 mg CO2/g adsorbent), TEPA-MCM-41 (112 mg CO2/g adsorbent) and TEPA-NaY (96 mg CO2/g adsorbent) under the same test condition. The results clearly suggest that the MSP (AS) synthesized using photonic industrial solid wastes via salt-templated aerosol route can be a potential and cost-effective adsorbent for CO2 capture. (C) 2012 Elsevier B.V. All rights reserved."
Aerosol-assisted deposition of Mn-Fe oxide catalyst on TiO2 for superior selective catalytic reduction of NO with NH3 at low temperatures
(2018-06-01)
Lin, Liang-Yi
;
Lee, Chung-Yu
;
Zhang, You-Ren
;
Bai, Hsunling
;
環境工程研究所
A series of Me-Fe/TiO2 catalysts was prepared via an aerosol-assisted deposition method, and used for the selective catalytic reduction of NO with NH3 (NH3-SCR) for the first time. Experimental results show that the spray-deposition Mn-Fe/TiO2, denoted Mn-Fe/TiO2(SD), demonstrates high NH3-SCR activity (> 95% conversion) with high N-2 selectivity (> 90%) at temperatures as low as 80-150 degrees C at a space velocity of 50,000 h(-1). Also, the benefits of the spray deposition for preparing Mn-Fe/TiO2 are highlighted by comparison with co precipitation and wet impregnation. This efficient and reliable technique offers attractive opportunities for largescale manufacture of promising materials with superior deNO catalytic performances.
Bifunctional mesoporous Cu-Al-MCM-41 materials for the simultaneous catalytic abatement of NO(x) and VOCs
(2009-01-01)
Karthik, Mani
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Lin, Liang-Yi
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Bai, Hsunling
;
環境工程研究所
;
Institute of Environmental Engineering
This study explored the possibility of using waste organic solvent as the source of volatile organic compound (VOC) and it served as a reducing agent of selective catalytic reduction (SCR) deNO(x) process, in which the VOC itself can be catalytically oxidized on the mesoporous Cu and/or Al substituted MCM-41 catalysts. The synthesized Cu-Al-MCM-41 catalysts were extensively characterized by powder low-angle X-ray diffraction (XRD), N(2) adsorption-desorption measurements, transmission electron microscopy (TEM), UV-Visible diffuse reflectance spectroscopy (UV-Vis DRS), (27)Al magic angle spinning-nuclear magnetic resonance spectroscopy (MAS-NMR), electron paramagnetic resonance spectroscopy (EPR) and inductively coupled plasma-mass spectrometer (ICP-MS) analysis. The XRD, TEM and N2 adsorption-desorption studies clearly demonstrated the presence of a well ordered long range hexagonal array with uniform mesostructures. The Cu-Al-MCM-41 materials showed a better long-term-stability than that of copper ion-exchanged H-ZSM-5 (Cu-ZSM-5) zeolite. The Cu-Al-MCM-41 material was found to be an efficient catalyst than that of Cu-MCM-41 without aluminum for the simultaneous catalytic abatement of NO(x) and VOCs, which was attributed to the presence of well dispersed and isolated Cu(2+) ions on the Cu-Al-MCM-41 catalyst as observed by UV-Vis DRS and EPR spectroscopic studies. And the presence of aluminum (Al(3+) ions) within the framework of Cu-Al-MCM-41 stabilized the isolated Cu(2+) ions thus it led to higher and stabilized activity in terms of NO(x) reduction. (C) 2008 Elsevier Inc. All rights reserved.
Bifunctional mesoporous Cu-Al-MCM-41 materials for the simultaneous catalytic abatement of NOx and VOCs
(2009-01-01)
Karthik, Mani
;
Lin, Liang-Yi
;
Bai, Hsunling
;
環境工程研究所
;
Institute of Environmental Engineering
This study explored the possibility of using waste organic solvent as the source of volatile organic compound (VOC) and it served as a reducing agent of selective catalytic reduction (SCR) deNO(x) process, in which the VOC itself can be catalytically oxidized on the mesoporous Cu and/or Al substituted MCM-41 catalysts. The synthesized Cu-Al-MCM-41 catalysts were extensively characterized by powder low-angle X-ray diffraction (XRD), N-2 adsorption-desorption measurements, transmission electron microscopy (TEM), UV-Visible diffuse reflectance spectroscopy (UV-Vis DRS), Al-27 magic angle spinning-nuclear magnetic resonance spectroscopy (MAS-NMR), electron paramagnetic resonance spectroscopy (EPR) and inductively coupled plasma-mass spectrometer (ICP-MS) analysis. The XRD, TEM and N2 adsorption-desorption studies clearly demonstrated the presence of a well ordered long range hexagonal array with uniform mesostructures. The Cu-Al-MCM-41 materials showed a better long-term-stability than that of copper ion-exchanged H-ZSM-5 (Cu-ZSM-5) zeolite. The Cu-Al-MCM-41 material was found to be an efficient catalyst than that of Cu-MCM-41 without aluminum for the simultaneous catalytic abatement of NOx and VOCs, which was attributed to the presence of well dispersed and isolated Cu2+ ions on the Cu-Al-MCM-41 catalyst as observed by UV-Vis DRS and EPR spectroscopic studies. And the presence of aluminum (Al3+ ions) within the framework of Cu-Al-MCM-41 stabilized the isolated Cu2+ ions thus it led to higher and stabilized activity in terms of NOx reduction. (C) 2008 Elsevier Inc. All rights reserved.
Continuous generation of mesoporous silica particles via the use of sodium metasilicate precursor and their potential for CO(2) capture
(2010-12-01)
Lin, Liang-Yi
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Bai, Hsunling
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環境工程研究所
;
Institute of Environmental Engineering
Fast synthesis of spherical mesoporous silica materials using the inorganic silica source of sodium metasilicate (Na(2)SiO(3 center dot)9H(2)O) via aerosol spray of evaporation induced self-assembly method is presented in this study. The XRD, TEM and N(2) adsorption-desorption measurements indicated the presence of a well ordered hexagonal array with uniform mesostructures. The mesoporous silica spherical particles (MSPs) obtained via sodium metasilicate precursor, denoted as MSP(NaSi), possessed high specific surface areas (820-1060 m(2)/g), narrow pore size distributions (2.4-2.8 nm) and large pore volumes (0.60-0.88 cm(3)/g). Their particle sizes were smaller while the particle size distributions were narrower than the MSP made from the organic silica precursor of TEOS, denoted as MSP(TEOS). The MSPs were further applied as adsorbents for the capture of CO(2) greenhouse gas. It was demonstrated that the amine functionalized MSP(NaSi) adsorbent, TEPA/MSP(NaSi)-18, exhibited an adsorption capacity (67 mg CO(2)/g adsorbent) of only slightly less than that of MSP(TEOS) (83 mg CO(2)/g adsorbent), and its capacity is much higher than that of TEPA functionalized ZSM-5 zeolite (12 mg CO(2)/g adsorbent). The results suggested that MSPs synthesized using low-cost Na(2)SiO(3) via aerosol route can be a cost-effective mesoporous adsorbent for CO(2) capture. (C) 2010 Elsevier Inc. All rights reserved.
Continuous generation of mesoporous silica particles via the use of sodium metasilicate precursor and their potential for CO2 capture
(2010-12-01)
Lin, Liang-Yi
;
Bai, Hsunling
;
環境工程研究所
;
Institute of Environmental Engineering
Fast synthesis of spherical mesoporous silica materials using the inorganic silica source of sodium metasilicate (Na(2)SiO(3 center dot)9H(2)O) via aerosol spray of evaporation induced self-assembly method is presented in this study. The XRD, TEM and N-2 adsorption-desorption measurements indicated the presence of a well ordered hexagonal array with uniform mesostructures. The mesoporous silica spherical particles (MSPs) obtained via sodium metasilicate precursor, denoted as MSP(NaSi), possessed high specific surface areas (820-1060 m(2)/g), narrow pore size distributions (2.4-2.8 nm) and large pore volumes (0.60-0.88 cm(3)/g). Their particle sizes were smaller while the particle size distributions were narrower than the MSP made from the organic silica precursor of TEOS, denoted as MSP(TEOS). The MSPs were further applied as adsorbents for the capture of CO2 greenhouse gas. It was demonstrated that the amine functionalized MSP(NaSi) adsorbent, TEPA/MSP(NaSi)-18, exhibited an adsorption capacity (67 mg CO2/g adsorbent) of only slightly less than that of MSP(TEOS) (83 mg CO2/g adsorbent), and its capacity is much higher than that of TEPA functionalized ZSM-5 zeolite (12 mg CO2/g adsorbent). The results suggested that MSPs synthesized using low-cost Na2SiO3 via aerosol route can be a cost-effective mesoporous adsorbent for CO2 capture. (C) 2010 Elsevier Inc. All rights reserved.
Efficient Method for Recycling Silica Materials from Waste Powder of the Photonic Industry
(2013-05-07)
Lin, Liang-Yi
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Bai, Hsunling
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環境工程研究所
;
Institute of Environmental Engineering
An efficient and economic approach is proposed for the fast and direct recovery of silica materials from photonic waste powder. Unlike the conventional alkaline fusion method for the extraction of silica from waste materials, this method possesses advantages of a rapid and low-energy-consumed process with total recovery yield. The obtained mesoporous silica material, denoted as MCM-41(DU)-F, was recovered directly from photonic waste powder at room temperature with the assistance of cationic surfactant, hydrofluoric acid, and ammonia hydroxide. The recycled MCM-41(DU)-F with a high specific surface area (788 m(2)/g), ordered mesoporous structure (4.5 nm), and large pore volume (1.1 cm(3)/g) was used as support of tetraethylenepentamine (TEPA) for the capture of CO2 from a flue gas stream. The results demonstrated that TEPA-impregnated MCM-41(DU)-F had an adsorption capacity of 120 mg of CO2/g of adsorbent This is higher than the amount adsorbed by TEPA-MCM-41(NaSi) made from pure chemicals (113 mg of CO2/g of adsorbent) and TEPA-MCM-41(AF) made from alkaline fusion (112 mg of CO2/g of adsorbent) under the same testing conditions. This novel recycling process, which can improve cost effectiveness for the mass production of valuable mesoporous silica materials from cheap and abundant resources through convenient preparation steps, is surely beneficial from the viewpoint of economical use of photonic industrial waste powder.
Engineering stable Pt nanoparticles and oxygen vacancies on defective TiO2 via introducing strong electronic metal-support interaction for efficient CO2 photoreduction
(2020-06-01)
Lin, Liang-Yi
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Kavadiya, Shalinee
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He, Xiang
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Wang, Wei-Ning
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Karakocak, Bedia Begum
This work for the first time reports the promoting effect of strong electronic metal-support interaction (EMSI) in N/TiO2-V-O (V-O: oxygen vacancy) for gas-phase CO2 photoreduction. A novel in-situ surface hydrogenation was developed to prepare hydrogenated N/TiO2-V-O in a continuous, high throughput diffusion flame aerosol reactor. The combined results of various characterization techniques confirmed the presence of EMSI between N and defective TiO2-V-O resulted in the enhanced electronic density of N nanoparticles. Both the modulated electronic structure of N and surface oxygen vacancies simultaneously promoted the activation of surface adsorbed carbon intermediates and facilitated the separation of photogenerated charges, eventually boosting the photocatalytic activity of N/TiO2-V-O. The optimized N/TiO2-V-O demonstrated a high quantum yield of 1.49% with high CH4 selectivity (81%), which rendered 5.8- and 1.2-fold enhancements over its counterparts of TiO2-V-O and N/TiO2. More significantly, the EMSI also played a critical role in preserving the surface metallic Pt-0 and oxygen vacancies, and in sustaining high activity of the Pt/TiO2-V-O, whereas rapid catalytic deactivation are observed for both TiO2-V-O and Pt/TiO2.
Facile and surfactant-free route to mesoporous silica-based adsorbents from TFT-LCD industrial waste powder for CO2 capture
(2013-04-01)
Lin, Liang-Yi
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Bai, Hsunling
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環境工程研究所
;
Institute of Environmental Engineering
A surfactant-free preparation of mesoporous silica spherical particles, MSPs was developed using sodium silicate extracted from TFT-LCD industrial waste powder via aerosol spray route in this study. Inorganic acids including hydrochloric acids and nitric acids were employed to acidify the silicate supernatant to form activated silica precursors and the influence of acids in the activated silica precursors was studied. The MSPs(HNO3), which was synthesized in the presence of nitric acids exhibited high surface area (776 m(2)/g), mesopore size (5.3 nm) as well as large pore volume (1.15 cm(3)/g) and it was further applied as a support of adsorbent for CO2 capture. It was demonstrated that tetraethylenepentamine (TEPA)-impregnated MSPs(HNO3) adsorbent presents advantages of convenient synthesis, low cost and high adsorption performance (122 mg-CO2/g-adsorbent), which was superior to those of TEPA-SBA-15 and TEPA-MCM-41 manufactured from pure silica chemicals under the same test conditions. The results suggested that low-cost MSPs(HNO3) prepared using silicate solution from TFT-LCD waste powder via spray approach can be promising CO2 adsorbents. This novel process could also be employed for further extensible to other kinds of Si-related industrial wastes and benefit in large-scale production of highly valuable silica-based sorbents for environmental protection applications. (C) 2012 Elsevier Inc. All rights reserved.
Promotional effects of manganese on the structure and activity of Ce-Al-Si based catalysts for low-temperature oxidation of acetone
(2016-05)
Lin, Liang-Yi
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Bai, Hsunling
;
環境工程研究所
;
Institute of Environmental Engineering
Low-temperature catalytic oxidation of acetone over metal (M = Cu, Co, Ni, Mn, Fe)-modified cerium oxide supported on Al-containing MSPs (mesoporous silica particles) was studied. The activity tests on various mixed oxides of Cu-Ce, Co-Ce, Ni-Ce, Mn-Ce and Fe-Ce supported on Al-MSPs demonstrated that Ce was the main active species in catalytic oxidation of acetone, while Mn functioned as an appropriate promoter for improving the activity of Ce/Al-MSPs catalyst. The promoting effects of Mn on the structure and activity of Ce/Al-MSPs were investigated. Results showed that the amounts of Mn had significant influences on the catalyst structure, chemical state, redox behavior and surface adsorption ability of the catalysts. Among the catalysts studied, Mn-Ce/Al-MSPs with a Mn/Ce molar ratio of 2/1 was found to be the most active catalyst for achieving maximum acetone activity at temperature of 100-200 degrees C, and it showed much better catalytic performance in comparison with those of Ce/Al-MSPs and Mn/Al-MSPs alone. The superior activity could be attributed to the synergistic effect existing in MnCeOx mixed oxides, resulting in higher amount of Ce3+ and Mn4+ species and enhanced surface reducibility on the catalyst surface and improved acetone adsorption ability, as confirmed by the XPS, H-2-TPR and acetone-TPD analyses. In addition, Mn-Ce(2/1)/AI-MSPs showed a remarkable stability at 175 degrees C after being used for 55 h. (C) 2016 Elsevier B.V. All rights reserved.
Salt-induced formation of hollow and mesoporous CoOx/SiO2 spheres and their catalytic behavior in toluene oxidation
(2016-01-01)
Lin, Liang-Yi
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Bai, Hsunling
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環境工程研究所
;
Institute of Environmental Engineering
Hollow and mesoporous CoOx/SiO2 spheres (denoted as CoOx/hSiO(2) and CoOx/mSiO(2)) were synthesized via salt-assisted ultrasonic spray pyrolysis. Precursor solutions containing sodium silicate solution, a mineral acid (hydrochloric acid or nitric acid) and a cobalt salt were ultrasonically aerosolized and pyrolyzed. Results showed that CoOx/SiO2 spheres with hollow or mesoporous structure can be fabricated by using the NaCl and NaNO3 salts as in situ formed templates. Significantly, this approach avoids the need for post-calcination for template elimination, instead permitting aqueous removal with water. The influence of the sodium salts on the characteristics of CoOx/SiO2 spheres was investigated by means of XRD, nitrogen physisorption, SEM/TEM, ICP-MS, UV-Vis, XPS and H-2-TPR. On the basis of the experimental results, a possible mechanism on the formation of hollow and mesoporous spheres was proposed. The CoOx/SiO2 spheres were tested as catalysts for toluene oxidation. The mesoporous CoOx/mSiO(2) was found to exhibit superior activity to hollow CoOx/hSiO(2), probably attributed to a combination of several factors, including the predominant existence of a Co3O4 active phase, high surface Co3+ content, and easy reducibility of Co3+ at low temperature.
Salt-templated synthesis of Ce/Al catalysts supported on mesoporous silica for acetone oxidation
(2014-04-27)
Lin, Liang-Yi
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Bai, Hsunling
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環境工程研究所
;
Institute of Environmental Engineering
A series of bimetallic Ce/Al catalysts supported on mesoporous silica catalysts were prepared through fast salt-templated aerosol process in this study. The source of sodium silicate precursor was from the alkali-extraction of the opto-electronic industrial waste. The inorganic salt formed during the silicate acidification process was served as an effective and low-cost template, which could be simply removed by water washing at room temperature. The Ce/Al-SiO2 catalysts were fabricated under various aerosol-spraying temperatures, and the temperature effects on the structural and surface properties were investigated by XRD, nitrogen physisorption measurement, SEM/TEM, ICP-MS, Al-27 MAS-NMR, UV-vis spectra, H-2-TPR and NH3-TPD analyses. The catalytic behavior was further evaluated in terms of acetone oxidation. The results revealed that the catalytic oxidation of acetone is mainly governed by the surface redox property, along with the acidity of the catalysts. The Ce/Al-SiO2-300, with high surface acidity and strong surface reducibility, appeared to have the best acetone catalytic performance at temperatures of 100-300 degrees C and its T-90 was at 165 degrees C under acetone inlet concentration of 1000 ppmv and GHSV of 15,000 h(-1). Furthermore, compared with literature data which catalysts were prepared using commercial silicon source and traditional organic surfactant templates, Ce/Al-SiO2-300 showed a comparable catalytic performance, indicating the great potential application of Ce/Al-SiO2 catalysts for the catalytic oxidation of acetone. (C) 2013 Elsevier B.V. All rights reserved.
Silica materials recovered from photonic industrial waste powder: Its extraction, modification, characterization and application
(2011-08-15)
Lin, Liang-Yi
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Kuo, Jien-Ting
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Bai, Hsunling
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環境工程研究所
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Institute of Environmental Engineering
This study explored the possibility of recovering waste powder from photonic industry into two useful resources, sodium fluoride (NaF) and the silica precursor solution. An alkali fusion process was utilized to effectively separate silicate supernatant and the sediment. The obtained sediment contains purified NaF (>90%), which provides further reuse possibility since NaF is widely applied in chemical industry. The supernatant is a valuable silicate source for synthesizing mesoporous silica material such as MCM-41. The MCM-41 produced from the photonic waste powder (PWP), namely MCM-41(PWP), possessed high specific surface areas (1082 m(2)/g), narrow pore size distributions (2.95 nm) and large pore volumes (0.99 cm(3)/g). The amine-modified MCM-41 (PWP) was further applied as an adsorbent for the capture of CO2 greenhouse gas. Breakthrough experiments demonstrated that the tetraethylenepentamine (TEPA) functionalized MCM-41(PWP) exhibited an adsorption capacity (82 mg CO(2)/g adsorbent) of only slightly less than that of the TEPA/MCM-41 manufactured from pure chemical (97 mg CO(2)/g adsorbent), and its capacity is higher than that of TEPA/ZSM-5 zeolite (43 mg CO(2)/g adsorbent). The results revealed both the high potential of resource recovery from the photonic solid waste and the cost-effective application of waste-derived mesoporous adsorbent for environmental protection. (C) 2011 Elsevier B.V. All rights reserved.
Titanium Dioxide/Zeolite Catalytic Adsorbent for the Removal of NO and Acetone Vapors
(2009-10-01)
Jan, Yan-Huei
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Lin, Liang-Yi
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Karthik, Mani
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Bai, Hsunling
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環境工程研究所
This study delineates a simple and versatile approach for the removal of nitrogen monoxide (NO) and volatile organic vapors over composites of titanium dioxide (TiO(2)) catalyst/zeolite adsorbent under ultraviolet (UV) irradiation at ambient temperature. The catalytic adsorbents with different TiO(2)/H-ZSM-S zeolite ratios were prepared by a simple insipient wetness impregnation method. It was found that a 60%/40% weight ratio of TiO(2)/H-ZSM-5 composite is most effective and can achieve over 90% efficiency for the removal of NO and acetone vapors. This composite also showed a better long-term activity than that of bulk TiO(2) photocatalyst or zeolite adsorbent. The experimental results revealed that photocatalytic decomposition of NO was dramatically enhanced in the presence of acetone. NO also promoted the acetone oxidation under humid conditions. Furthermore, the co-existence of acetone and NO in the gaseous stream could reduce acid accumulation on the surface of the catalyst as confirmed by Fourier-transform infrared spectroscopy. Thus, the TiO(2)/zeolite catalytic adsorbent could have a high potential for the removal of multiple air pollutants in the indoor air environment.