鋁與水化學產氫之研究

Chemical Reaction for Hydrogen Generation from Aluminum and Water System

鄧信德(Hsin-Te Teng) ； 王宏文(Hong-Wen Wang)

《化學》 70卷3期 (2012/09) Pp. 221-236

https://doi.org/10.6623/chem.2012021

摘要

利用第一族過渡金屬氧化物催化鋁/水系統產氫，經由Arrhenius equation理論求得活化能，證實氧化物皆具有催化活性，純鋁的活化能為164.86 kJ/mol，氧化物催化效果最佳的是Co_3O_4 (70.42kJ/mol)，而最差的是ZnO (140.15 kJ/mol)，透過這相對的關係可以印證造成反應速率差異的現象為每個氧化物在鋁/水產氫系統中的催化效果不同。在氧化物催化鋁/水產氫的重複添加系統，實驗證明為反應後副產物(Al(OH)_3)的催化效應，藉由改變Al(OH)_3的材料特性 (粒徑、結晶、表面積)則會影響其反應速率，結果顯示，當粒徑小，結晶性差，表面積大的材料性質，催化鋁/水產氫系統具有良好的催化活性 (31.56 kJ/mol)。最後以Al:Al(OH)_3:H_2O = 1:8:50為最佳參數，此反應條件在兩個小時內產氫效率高達94.9%，將此應用於燃料電池上，所產生的氫氣確實能使燈泡發光。從鋁與水的反應中，本研究揭露出一種快速而簡易的產氫方式。

關鍵字

鋁粉 ； 水 ； 產氫 ； 活化能

並列摘要

The present study proved that the first family transition metal oxide all facilitated the hydrogen generation from aluminum(Al)/water system by reduction of activation energy. All activation energies were calculated using Arrhenius equation. The activation energies obtained for the pure aluminum is 164.86 kJ/mol. The best catalytic effect is obtained from Co_3O_4, whose activation energy is only 70.42 kJ/mol. The weakest catalytic effect is obtained from ZnO, whose activation energy is 140.15 kJ/mol. The calculation of activation energy provides an insight of the catalytic effect of transition metal oxide on Al/water system. It was also found that the consecutive addition of metal Al into water could result in an increasing rapid hydrogen generation rate. Experiments proved that the catalytic effect of reaction by-products (Al(OH)_3) exhibited profound effect on the generation rate. The catalytic effect of Al(OH)_3 greatly depends on their particle size, crystallinity, surface area. Small particle size, high surface area and poor crystallinity of Al(OH)_3 increases the hydrogen generation rate significantly. Al(OH)_3 has a strong catalytic effect on aluminum/water system for its hydrogen generation. The activation energy of this system is only 31.56 kJ/mol. For the best combination of this study, Al:Al(OH)_3:H_2O = 1:8:50, its hydrogen production efficiency achieves 94.9% within two hours. When the hydrogen generated was applied to a fuel cell as a power source, it indeed turns on the bulb. The present study has discovered a fast and simple way to generate hydrogen gas from Al/water system.

並列關鍵字

Aluminum powder ； Water ； Hydrogen generation ； Activation energy