Browsing by Author "Lin, Yu-Kai"

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Efficient hydrogen production using Cu-based catalysts prepared via homogeneous precipitation
(2009)
Lin, Yu-Kai
;
Su, Yi-Han
;
Huang, Yun-Hsin
;
Hsu, Chia-Jung
;
Hsu, Yu-Kuei
We report here preparation of multi-composition Cu/ZnO/Al(2)O(3) (CZA) catalyst by homogeneous precipitation (HP) method using urea treatment. Compared to the conventional co-precipitation (CP) method, the HP method used here improves the uniformity of metal mixing through homogeneous generation of hydroxide ions as a result of hydrolysis of urea in the solution. In this study, optimization of the conditions to prepare CZA catalyst was achieved by adjusting the urea concentration, amount of water, reaction temperature and reaction time; to control the pH value. The HP-derived CZA particles exhibited a characteristic flower-like morphology with a higher surface area, typically 78.5 m(2)/g as measured by the BET analysis, as compared to the CP-derived CZA catalysts. Induction coupled plasma and energy dispersive spectroscopy mapping results further confirmed the homogeneity of HP-CZA components and highly uniform dispersion of the active metal. Significantly lowering and a narrower range of the reduction temperature for HP-CZA is observed. An improved performance in methanol reforming reaction, in terms of methanol conversion, yield of hydrogen production, and higher carbon dioxide selectivity, has been achieved. Furthermore, the concentration of carbon monoxide can be further reduced by employing CeO(2) and ZrO(2) to modify the support, which also results in reduced reduction temperature and improved performance. Among the modified catalysts, HP-CZCZ catalyst showed the highest methanol conversion and rate of hydrogen production, simultaneously with reduced concentration of CO. Moreover, only 20 mg of catalyst loading yielded 98% methanol conversion rate under more than 8500 h(-1) GHSV. In future, not only can this method be used to synthesize other multi-composition materials with high homogeneity, but also our approach presents opportunity for production of a highly active catalyst for efficient generation of hydrogen for fuel cell applications.
Mirrored Prominent Deck B Phenomenon: Frequent Small Losses Override Infrequent Large Gains in the Inverted Iowa Gambling Task
(2012-10-16)
Lin, Ching-Hung
;
Song, Tzu-Jiun
;
Lin, Yu-Kai
;
Chiu, Yao-Chu
;
應用化學系
Since Bechara et al. pioneered its development, the Iowa Gambling Task (IGT) has been widely applied to elucidate decision behavior and medial prefrontal function. Although most decision makers can hunch the final benefits of IGT, ventromedial prefrontal lesions generate a myopic choice pattern. Additionally, the Iowa group developed a revised IGT (inverted IGT, iIGT) to confirm the IGT validity. Each iIGT trial was generated from the trial of IGT by multiplying by a "2" to create an inverted monetary value. Thus, bad decks A and B in the IGT become good decks iA and iB in the iIGT; additionally, good decks C and D in the IGT become bad decks iC and iD in the iIGT. Furthermore, IGT possessed mostly the gain trials, and iIGT possessed mainly the loss trials. Therefore, IGT is a frequent-gain-based task, and iIGT is a frequent-loss-based task. However, a growing number of IGT-related studies have identified confounding factors in IGT (i.e., gain-loss frequency), which are demonstrated by the prominent deck B phenomenon (PDB phenomenon). Nevertheless, the mirrored PDB phenomenon and guiding power of gain-loss frequency in iIGT have seldom been reexamined. This experimental finding supports the prediction based on gain-loss frequency. This study identifies the mirrored PDB phenomenon. Frequent small losses override occasional large gains in deck iB of the iIGT. Learning curve analysis generally supports the phenomenon based on gain-loss frequency rather than final outcome. In terms of iIGT and simple versions of iIGT, results of this study demonstrate that high-frequency loss, rather than a satisfactory final outcome, dominates the preference of normal decision makers under uncertainty. Furthermore, normal subjects prefer "no immediate punishment" rather than "final reward" under uncertainty.
Nanostructured Zinc Oxide Nanorods with Copper Nanoparticles as a Microreformation Catalyst
(2009)
Lin, Yan-Gu
;
Hsu, Yu-Kuei
;
Chen, San-Yuan
;
Lin, Yu-Kai
;
Chen, Li-Chyong