Browsing by Author "Hung, Chin-Te"

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Adsorption behaviors of organic vapors using mesoporous silica particles made by evaporation induced self-assembly method
(2008-04-01)
Hung, Chin-Te
;
Bai, Hsunling
;
環境工程研究所
;
Institute of Environmental Engineering
Spherical mesoporous silica materials with controllable surface area and uniform pore size were synthesized via evaporation induced self-assembly (EISA) method in this study. Both well-ordered and less-ordered mesoporous silica particle (MSP) adsorbents were made via adjusting the surfactant/silica precursor molar ratio. And the relationships between the physical characteristics of MSP adsorbents and the acetone adsorption behaviors were examined for the first time. The results indicated that an increase in the specific surface area results in an increase in the acetone adsorption capacity. But if a further increase in the surface area causes a less structured adsorbent then the acetone adsorption capacity could become less even though the specific surface area is of the highest value of 1337 m(2)/g. ne acetone adsorption capacity of well-ordered MSP adsorbent is more than twice of that of the commercial ZSM-5 zeolite adsorbent due to its relatively higher surface area and uniform pores. The well-ordered structure of MSP also leads to higher acetone adsorption efficiency and a sharper breakthrough curve due to fast pore diffusion. (C) 2008 Elsevier Ltd. All rights reserved.
Fabrication of CNTs with controlled diameters and their applications as electrocatalyst supports for DMFC
(2011-03-01)
Lo, An-Ya
;
Yu, Ningya
;
Huang, Shing-Jong
;
Hung, Chin-Te
;
Liu, Shou-Heng
A facile synthesis procedure based on chemical vapor deposition (CVD) process has been developed to fabricate carbon nanotubes (CNTs) with controlled diameters and high yields utilizing Fe-containing ordered hexagonal mesoporous silicas (HMSs) such as MCM-41 and SBA-15 having varied pore sizes as the catalysts as well as the templates. It is found that unlike Fe/HMS catalysts prepared by co-precipitation method, samples prepared by the impregnation method gave rise to multi-wall CNTs with uniform diameters, which were largely dictated by the pore size of the Fe/HMS catalysts. Among these uniform MWCNTs, sample with a larger diameter (>= 8 nm) was found to be more favorable as support for Pt catalyst, leading to a homogeneous dispersion of metal nanoparticles. Consequently, the Pt/CNT electrocatalysts so prepared gave rise to superior methanol oxidation activities as well as tolerances for CO poisoning compared to Pt supported on commercial single-wall CNT (Pt/SWCNT) and XC-72 activated carbon (Pt/XC-72) having a similar metal loading. (c) 2011 Elsevier B.V. All rights reserved.
Syntheses of carbon porous materials with varied pore sizes and their performances as catalyst supports during methanol oxidation reaction
(2012-12-01)
Lo, An-Ya
;
Hung, Chin-Te
;
Yu, Ningya
;
Kuo, Cheng-Tzu
;
Liu, Shang-Bin
Carbon porous materials (CPMs) with extended ranges of pore size and morphology were replicated using various porous silicas, such as zeolites, mesoporous silicas, and photonic crystals, as templates by means of chemical vapor infiltration (CV!) method. The micro-, meso-, and macro-porous carbons so fabricated were adopted as supports for the metal (Pt) catalyst for direct methanol fuel cells (DMFCs), and the supported Pt/CPM electrocatalysts were characterized by a variety of different spectroscopic/analytical techniques, viz transmission electron microscopy (TEM), Raman, X-ray photoelectron spectroscopy (XPS), gas physisorption/chemisorption analyses, and cyclic voltammetry (CV). That these Pt/CPMs were found to exhibit superior electrocatalytic activities compared to the commercial Pt/XC-72 with a comparable Pt loading during methanol oxidation reaction (MOR) is attributed to the presence of Pt nanoparticles (NPs; typically 1-3 nm in size) that are highly dispersed in the CPMs, facilitating an improved tolerance for CO poisoning. While the MOR activity observed for various Pt/CPMs tend to increase with increasing pore size of the carbon supports, Pt catalyst supported on carbon substrates possessing microporosities was found to have superior stability in terms of tolerance for CO poisoning than those with greater pore size or having meso- and macroporosities. (C) 2012 Elsevier Ltd. All rights reserved.
Syntheses of carbon porous materials with varied pore sizes and their performances as catalyst supports during methanol oxidation reaction
(2012-12-01)
Lo, An-Ya
;
Hung, Chin-Te
;
Yu, Ningya
;
Kuo, Cheng-Tzu
;
Liu, Shang-Bin
Carbon porous materials (CPMs) with extended ranges of pore size and morphology were replicated using various porous silicas, such as zeolites, mesoporous silicas, and photonic crystals, as templates by means of chemical vapor infiltration (CV!) method. The micro-, meso-, and macro-porous carbons so fabricated were adopted as supports for the metal (Pt) catalyst for direct methanol fuel cells (DMFCs), and the supported Pt/CPM electrocatalysts were characterized by a variety of different spectroscopic/analytical techniques, viz transmission electron microscopy (TEM), Raman, X-ray photoelectron spectroscopy (XPS), gas physisorption/chemisorption analyses, and cyclic voltammetry (CV). That these Pt/CPMs were found to exhibit superior electrocatalytic activities compared to the commercial Pt/XC-72 with a comparable Pt loading during methanol oxidation reaction (MOR) is attributed to the presence of Pt nanoparticles (NPs; typically 1-3 nm in size) that are highly dispersed in the CPMs, facilitating an improved tolerance for CO poisoning. While the MOR activity observed for various Pt/CPMs tend to increase with increasing pore size of the carbon supports, Pt catalyst supported on carbon substrates possessing microporosities was found to have superior stability in terms of tolerance for CO poisoning than those with greater pore size or having meso- and macroporosities. (C) 2012 Elsevier Ltd. All rights reserved.