甲烷轉化為甲醇或甲醛是天然氣經濟利用的重要的議題，甲醇(甲醛)是一種有價值的燃料和合成烴產品的原料。目前工業上是利用甲烷蒸氣重組將甲烷轉化成合成氣再合成甲醇(甲醛)，但甲烷蒸氣重組是一個高吸熱的反應，所以甲烷直接合成甲醇或甲醛是一個具有經濟效益的反應。本研究先以文獻常用於之觸媒Cu/ZSM-5，使用三種不同型態ZSM-5 (NaZSM-5、NH4ZSM-5、HZSM-5)以離子交換法製備觸媒，並探討其對甲烷部分氧化轉化活性和產率之影響，實驗結果顯示Cu/ HZSM-5反應性最高，可歸因於其中Cu含量最高。由低溫升至375-475℃範圍先發生完全氧化反應，更高溫才開始產生部分氧化產物，包含H2、CO與HCHO，推測是由於完全氧化產物參與導致部分氧化產物生成，測試結果顯示部分氧化產物主要是透過氧化性甲烷蒸汽重組反應所生成。接著討論不同反應條件下對氧化性甲烷蒸汽重組反應的影響，我們改變S/M、M/O比例以及WHSV，實驗結果顯示當M/O = 7和S/M = 1時部分氧化產物的產率最高，另外當WHSV較大(低轉化率)時只會產生二氧化碳和水，而WHSV較小(高轉化率)時部分氧化產物產率會增加。最後比較不同金屬(銅、鐵、鎳)擔載於HZSM-5對甲烷部分氧化反應之差異，結果顯示Cu/HZSM-5有最高的甲烷轉化率與最高的部分氧化產物產率，Fe/HZSM-5次之，而Ni/HZSM-5僅產生二氧化碳和水。

Methane direct conversion to methanol or formaldehyde is important for the application of natural gas. Methanol (formaldehyde) is a valuable fuel and is also a raw material for synthesizing various hydrocarbon products. The present production of methanol (formaldehyde) in the industry is a two-step method, involving methane reforming into and methanol synthesis from syngas of which methane reforming. Therefore, methane direct conversion to methanol or formaldehyde is a cost-effective reaction. In this study, Cu/ZSM-5, a commonly used catalyst for the partial oxidation of methane. NaZSM-5, NH4ZSM-5 and HZSM-5, are prepared by ion-exchanged method and tested. Cu/HZSM-5 appears to be the best catalyst, attributable to its highest Cu loading. The total oxidation of methane occurs at low temperature, while the partial oxidation products like CO, H2 and HCHO are observed at high temperature. This is confirmed that from total oxidation participate in the methane conversion via oxidative steam reforming. The ratios of S/M, M/O and WHSV are varied for optimizing the yield of partial oxidation products. The results showed that the yield of partial oxidation products is the highest when M/O = 7 and S/M = 1. In addition, at high WHSV when the conversion is low, only CO2 and H2O are observed, but when the conversion is high the yield of CO, H2, HCHO increase. The last part compares the partial oxidation of methane with different metals (Cu, Fe and Ni) supported on HZSM-5. The results show that Cu/HZSM-5 has the highest yield of CO, H2 and HCHO. The next is Fe/HZSM-5, but only CO2, H2O are observed on Ni/HZSM-5.

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