壹、脫鎂葉綠素之衍生物形態研究以及其可能之應用─對氫氣之作用 貳、脫鎂葉綠素之氫氣吸附與釋放特性之研究 參、一種基於自動上鍊機構之能量收集方式

1.Derivative Morphologies of Pheophytins And Their Possible Applications- Effect on H2 2.Hydrogen Adsorption And Release by Pheophytin 3.Energy Harvesting Based on Self-Winding Mechanism

黃均霖(Jyun-Lin Huang)

指導教授 ： 廖重賓

國立虎尾科技大學/電機資訊學院/光電與材料科技研究所/碩士(2015年)

摘要

壹、本研究以第一原則量子模擬軟體Dmol3計算脫鎂葉綠素分子(pheophytin)之原始及衍生結構之基態能量，因而指出一種可能的脫鎂葉綠素衍生型態已然存在，並利用可見光頻譜和實驗加以驗證。亦即，模擬過程中發現了脫鎂葉綠素會衍生出一種能量較低的分子結構，其特徵是：於卟?環上的氮原子皆呈現N-H單鍵之飽和狀態，即原始的脫鎂葉綠素的兩個氮原子雙鍵結構改變為單鍵結構，而相鄰的碳原子的形式電荷為+1，維持三個鍵。這種低能量分子結構構咸信形成一種離子的傳輸途徑，特別是在催化氫氣的過程中。在一燃料電池的架構下，我們發現氫氣分子在接近上述脫鎂葉綠素的半衍生態時，氫氣分子會被拉開分成兩個氫離子並因為化學電動勢而釋出電子至外部電路。故此半衍生態脫鎂葉綠素屬於重要的燃料電池催化劑，而全衍生態脫鎂葉綠素則是反應後氫離子的逸出通道。

貳、本研究係由懷疑脫鎂葉綠素的氮原子具有吸附氫氣的特性開始，藉由第一原理量子力學模擬軟體之計算以發現可能的機制與能量變化，最後透由實體實驗加以定量。實驗分做對照組和實驗組，對照組的氫氣吸附體是空白宣紙，實驗組之氫氣吸附體為沉積脫鎂葉綠素的宣紙，而氫氣的來源是由電解產生，實驗環境在常溫常壓下進行。藉由氫氣感測器來監測浮游於空間中氫氣量的變化，發現對照組氫氣量維持穩定，24小時僅下降0.42%，而實驗組則有明顯減少，在24小時內共減少1.12 mmol的氫氣分子，約28.4%，亦即吸附速率為46 μmole H2/hr。在釋放氫氣量測的部份，將吸附氫氣的脫鎂葉綠素宣紙以逐步加溫方式釋放H2，兩個溫度感測器分別量測頂部與底層的溫度數值做平均，實驗從室溫的25.1、36.2、48.4、60.3℃階梯上升，每3個小時調整一次溫度，溫度與釋放速率的關係為分別為26、62、114 μmole/hr。加溫釋放氫氣實驗出現大約在48℃左右出現一較高的釋放速率梯度。總釋出量約為原總吸附量的35%。

參、目前已知的電磁感應發電模組皆利用磁性材料與磁感應線圈間之磁力線切割動作來產生電能，再將電能儲存於儲電裝置。其過程中需提供一持續的外力使兩種材料保持切割磁力線狀態。本研究在於提出並探討如何減少外力的提供次數及提升發電效能的新方式。吾人設計並開發一種具有自動上鍊機制的發電裝置，能在攜帶、或震動的過程中藉由內裝的轉動擺陀來持續提供所需的外力。此裝置包括上鍊擺陀、磁性元件及磁感元件。上鍊擺陀做動時可旋緊發條儲存動能，磁性磁感元件共有兩組，第一磁性磁感元件位元於上鍊擺陀，隨上鍊擺陀做動而產生電能；第二磁性磁感元件置於傳動軸，隨傳動軸旋轉而產生電能。目前以銣鐵硼磁鐵做為磁性元件直徑=15mm、厚度= 2.5mm，發電頻率為21 Hz，單一磁感元件的輸出功率約為7.7 mW。

關鍵字

脫鎂葉綠素 ； 密度泛函理論 ； 氫氣催化 ； 氫氣吸附 ； 儲氫材料 ； 自動上鍊 ； 儲電裝置

並列摘要

1.A new derivative morphology of pheophytin was proposed and supported by spectral comparison and experimental verification. In short, when in the presence of an entering hydrogen gas molecule (or a proton pair, after their electrons were stripped by external means), a lower-energy structure of pheophytin existed wherein each nitrogen atom on its porphyrin ring was saturated with N–H bond. That is, the originally two double bonds associated with the two N atoms became single bonds, and all adjacent carbon atoms became carrying formal charge +1 and thus possessing only three bonds. Such a low-energy structure was found to constitute a general purpose proton traverse path, especially in a pheophytin-catalyzed hydrogen decomposition process.

2.By way of 1st-principle quantum simulations, the site with nitrogen atoms within the porphyrin ring of a pheophytin was suspected to be capable of adsorbing hydrogen molecules. Experiments were thus conducted to verify such speculation. In a hydrogen gas filled space, both samples of the control and experimental groups were installed, with the former being only thirty pieces of calligraphy papers spanning an area of about 3000cm2, and the latter being such papers deposited with pheophytin. Under room temperature and pressure, the installed hydrogen gas sensor indicated that in the control group, hydrogen gas content varied little, diminishing only 0.42% in 24 hours, while in the experimental group a total of 1.12 mmol floating hydrogen was decreased, equivalent to an adsorption rate of about 46 μmole H2 / hr. On the front of hydrogen gas release, samples with adsorbed hydrogen were heated to release H2. With gradually increased temperature steps per 3 hours at 25, 36, 48, 60 ℃, respectively, the rate of release were found to be about 26, 62, and 114 μmole/hr, respectively. A high slope in the hydrogen release rate was spotted to be at about 48 ℃. Overall, the net release fraction was about 35% of the originally adsorbed quantity.

3.Currently, most known magnet-based power generating devices are relying on the relative movement of magnetic flux and sensing coils, which provides the desired electromotive force first and then capacitors are made ready to stored thus generated power. However, this energy harvesting process ceases when the external mechanical work is no long supplied. In this research, a methodology is realized and presented in which the above energy harvesting continues even after the stoppage of external oscillation. Namely, a self-winding mechanism with a magnetic oscillating hammer was designed and a prototype made to verify the practicality of such idea.
In the conducted experiment, the oscillator hammer and gear assembly were designed and made using 3D printing machine. With NdFeB magnet of the size diameter = 15mm, thickness = 2.5mm, and coil of the size: diameter = 16mm, thickness = 5mm, the output power of 7.7 mW was obtained.

並列關鍵字

pheophytin ； density functional theory ； hydrogen catalyzed ； adsorption of hydrogen ； hydrogen-storing ； materials ； self-winding ； energy harvesting

參考文獻

[24] 衣寶廉，2005，燃料電池─原理與應用，五南圖書出版，台北。

[5] Hohenberg, P., & Kohn, W., (1964), ”Inhomogeneous electron gas”, Physical review, 136(3B), B864.

[6] Kohn, W., & Sham, L. J., (1965). “Self-consistent equations including exchange and correlation effects”, Physical Review, 140(4A), A1133.

[7] Slater, J. C., (1951), “A simplification of the Hartree-Fock method”, Physical Review, 81(3), 385.

[8] Perdew, J. P., Burke, K., & Ernzerhof, M., (1996), “Generalized gradient approximation made simple”, Physical review letters, 77(18), 3865.