臺灣博碩士論文加值系統

本研究以甘胺酸燃燒法製備具有高表面積之多孔性赤銅鐵礦化合物CuCr1-xFexO2奈米粉末作為銅基觸媒的前驅物，探討CuCr1-xFexO2奈米粉末中的Fe含量多寡對於在甲醇水蒸氣下的還原行為以及產氫性能之影響。甲醇水蒸氣將Cu粒子在非還原氣氛下以低溫還原至氧化物擔體表面，甚至不需經過無須經過一般商用觸媒所需的活化過程即可使用。並經由控制Cu粒子尺寸在奈米等級來提升觸媒表面積與分散性。由XRD圖在200C時便可觀察到銅金屬相的繞射峰，以SEM觀察經過甲醇水蒸氣還原後的粉末，保持著多孔狀的結構並有極細微的銅粒子均勻分布在表面，其比表面積隨著鐵元素比例的下降由4.7 m2/g變化至28.56 m2/g，再由TEM觀察其微結構同時以EDX確認鐵的含量。產出之氣體則由配備TCD偵測器之GC分析後計算產率。 

The delafossite structure CuCr1-xFexO2 nanopowders (x = 0-1) was successfully synthesized by self-combustion glycine nitrate process (GNP) which has much higher surface area than bulk powder prepared by traditional solid state reaction. In this study, CuCr1-xFexO2 nanopowders as a precursor for copper based catalyst were applied to steam reforming of methanol (SRM) process for hydrogen production. Catalytic performance was enhanced with the nanoization of CuCr1-xFexO2 powders which leads to a higher surface area and the well dispersion of copper particles. Furthermore, CuCr1-xFexO2 nanopowders could be directly reduced by methanol steam without the typically activation process in hydrogen. Changes of CuCr1-xFexO2 nanopowders were determined by the X-ray diffraction (XRD) analysis. The cotton candy-like porous structure and the dispersion of Cu particles after the SRM process were revealed by scanning electron microscopy (SEM) together with the EDX elemental analysis. Microstructure of as-combusted nanopowders was determined by a transmission electron microscopy (TEM). The BET measurement showed the surface area of self-combusted CuCr1-xFexO2 nanopowders was over ten times larger than the powder prepared by traditional solid-state reaction and basically increased with the iron contents decreased. The production rate of hydrogen was analyzed with a gas chromatograph (GC) equipped with a thermal conductivity detector (TCD).

TABLE OF CONTENTS

摘 要 ii
ABSTRACT iii
誌 謝 v
TABLE OF CONTENTS vi
List of tables viii
List of figures ix
Chapter 1 Introduction 1
Chapter 2 Literature review 3
2.1 Delafossite structure 3
2.2 Self-combusted Glycine nitrate process 5
2.3 Copper based catalyst 9
2.4 Methanol reforming 11
Chapter 3 Experimental details 19
3.1 Experimental reagents 19
3.2 Experimental gases 19
3.3 Precursor preparation 20
3.4 Thermal treatment of CuCr1-xFexO2 nanopowder in nitrogen flow 22
3.5 Schematic diagram of the experiment system 24
3.6 Characteristic analysis 26
3.6.1 Crystalline determination 26
3.6.2 Scanning electron microscope image observation 27
3.6.3 Transmission electron microscopy 29
3.6.4 The specific surface area measurement 30
3.6.5 Gas chromatography 31
Chapter 4 Result and discussion 33
4.1 X-ray analysis of the as-combusted nanopowders 33
4.2 SEM images of as-combusted nanopowders 35
4.3 TEM analysis of as-combusted nanopowders 43
4.4 BET analysis of the as-combusted nanopowders 44
4.5 Characteristic of copper chromium iron oxide after steam reforming of methanol process 45
4.5.1 X-ray analysis of CuCr1-xFexO2 nanopowders after steam reforming of methanol process 45
4.5.2 SEM images of CuCr1-xFexO2 nanopowders after SRM process 51
4.5.3 Gas chromatograph analysis 57
Chapter 5 Conclusion 61
Reference 62
Paper Publication and Conference Presentations 66

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