燃料電池(fuel cell)為將來最具有發展的潔淨能源裝置，其以氫氣做為燃料，經反應後產生能量與無汙染的水與二氧化碳，反應物氫氣一般皆以甲醇部份氧化(POM)產生。本研究是利用桃園縣的廢棄稻殼，經過多重處理後所得稻殼灰分( rice husk ash，RHA)，並經由沈澱固著法製備擔載銅觸媒(Cu/Al2O3/RHA)。 本實驗利用熱重分析儀(TGA)決定製備時煅燒所需溫度，由氫氣程式升溫還原儀(TPR)探討觸媒還原難易程度，以N2O的氧化測其銅粒子大小與分散程度；以X光繞射分析儀(XRD)判斷觸媒之晶相;以掃描式電子顯微鏡(TEM)觀察觸媒形狀；以感應耦合電漿原子發射光譜(ICP-AES)測定觸媒組成。經由觸媒活性測試；反應溫度以473 K、498 K、523 K、548 K、573 K為操控變因，其它實驗變數包括進料之O2/CH3OH莫耳比(0.1~0.6)，其結果顯示反應溫度以523 K，進料比為0.3最為適當，因此條件下有最低的CO選擇率。提升氧醇比，降低氫氣選擇率但不影響甲醇轉化率。由四種(573 K、673 K、773 K、873 K)不同煅燒溫度所製備Cu/Al2O3/RHA觸媒，其中以673 K煅燒所得觸媒活性較高，因觸媒中平均銅粒徑最小且分散度最高。 In this work, the rice husk ash (RHA) was used as a catalyst support. The RHA-supported copper catalysts (Cu/Al2O3/RHA) were prepared by the deposition-precipitation technique. Production of hydrogen by partial oxidation of methanol (POM) over Cu/Al2O3/RHA catalysts was investigated. The catalysts were characterized by a variety of techniques, including N2O chemisorption, X–ray diffraction, inductively coupled plasma-atomic mission spectrometer, thermogravimetric analyzer, scanning electron microscopy, transmission electron microscopy, and temperature-programmed reduction. The copper surface area was determined by pulse chemisorption using N2O. We found a correlation between the copper surface area and catalytic activity. TEM images show that copper crystallites are spherical in shape. The particles size of copper increases with increasing the calcinaiton temperature. SEM observations show that these catalysts are formed with great structure of net. XRD analyses demonstrate that spinel CuAl2O4 is formed when the calcination temperature over 773 K . The results of the activity tests indicate that the Al2O3 promoter and the catalyst composition greatly influence the activity as well as the selectivity for H2 formation . The introduction of Al2O3 promoter not only helps to increase the activity of Cu/Al2O3/RHA catalyst but also improves the stability of the catalyst. The activity of Cu/Al2O3/RHA catalysts with different Al2O3 loading , O2/CH3OH ratio, calcination temperature and reaction temperature was optimized. The most suitable catalysts , prepared at 10wt.% Cu/1wt.% Al2O3/RHA, O2/CH3OH = 0.3, calcined at 673 K and reacted at 523 K show higher activity.
