本研究工作目的是建立氣相二次鍛燒奈米粒子合成系統，同時以製備的奈米粒子進行觸媒催化反應測試。藉由改變前驅物溶液的濃度及組成，我們可以改變製備的產物組成、粒子大小及形態，更進一步能夠透過氫氣還原及改變二次鍛燒系統的溫度來控制產物的氧化態。分析技術上以固定床觸媒催化活性測試系統來分析奈米粒子對甲烷燃燒的活性。而在二氧化碳重組反應中我們藉由連續紅外線偵測系統檢測反應氣體濃度及觀察觸媒床溫度，進而了解觸媒催化與反應吸、放熱情形。本研究方向會透過分析系統上的檢測，來探討奈米粒子的催化機制。
在第一部分實驗結果甲烷燃燒反應中，我們利用氣相方式來製備不同化學組成的單成分CuxO-NP與均質的複合式CuCeOx-NP之奈米觸媒，並探討單成分氧化銅奈米粒子與氧化銅/氧化鈰複合式奈米粒子對甲烷燃燒反應的催化活性影響。
材料分析方面我們使用SEM、XRD及DMA來分析奈米粒子的型態與晶格以及粒徑分佈，並利用觸媒催化活性測試、穩定性測試進行奈米觸媒催化能力的分析。複合式CuCeOx-NP奈米粒子具有低的起燃溫度(320 °C)以及高活性、選擇性及穩定性，藉由實驗結果我們得知添加鈰之後的奈米觸媒可以利用銅與鈰之間的界面金屬-擔體作用力效應來提升甲烷燃燒反應的催化活性，並且在Ce的莫耳比例等於0.17時達到最適化條件。同時研究中我們亦設計富氧、足氧以及貧氧的條件下進行催化活性之穩定性測試，以進一步了解甲烷燃燒反應的活性與穩定性之機制，其結果顯示在貧氧條件時，反應可能產生積碳造成觸媒的失活。而CuCeOx-NP在穩定性測試時，其在富氧、足氧及貧氧的條件下皆能維持其轉化率，顯示添加二氧化鈰有助於催化碳的氧化反應發生，以大幅降低積碳所造成的影響。而在貧氧條件下，二氧化鈰能使氧化銅能維持氧化態以避免不可逆還原而影響催化活性。同時，穩定性會隨著氧氣比例的增加而上升，此趨勢亦與觸媒表面除碳速率有關。
　　在第二部分實驗結果中，我們利用氣相二次鍛燒合成系統成功製備出不同氧化態的單成分CuxO-NP與複合式CuCeOx-NP-0.83及NiCeOx-NP-0.91奈米粒子，我們使用還原氣體氫氣透過改變第二次鍛燒的溫度來控制樣品的氧化態，以XRD分析佐證我們的結果，同時也進行SEM與DMA來分析樣品的形態及粒徑分布。我們也選用上述製備的氧化銅/氧化鈰、銅/氧化鈰、氧化鎳/氧化鈰、鎳/氧化鈰奈米粒子進行甲烷燃燒催化反應及二氧化碳重組反應。在甲烷燃燒反應中結果顯示添加鈰之後，觸媒轉化率也較為穩定，沒有失活現象的發生，原因為反應較容易在金屬-擔體界面處進行，此界面促進了沉積在氧化銅表面上的碳物質的氧化而減少積碳的生成。我們比較NiO-NP與NiCeOx-NP-0.91在二氧化碳重組反應中的效果，結果發現添加鈰可以增加二氧化碳的吸附速率，大幅提升反應轉化率，亦分析不同氧化態的NiCeOx-NP-0.91在二氧化碳重組反應的影響，證實反應機制皆為氧化鎳還原為金屬鎳再進行後續的反應，並且都能達到高的甲烷轉化效果。

In this study, we develop a gas-phase two-stage synthetic reaction system to fabricate nanoparticles for the applications in catalysis. Material properties, including particle size, crystallinity, elemental composition, and oxidation state, were characterized complementarily by a combination of physical, spectroscopic and microscopic approach. Our results shows that the material properties of hybrid nanoparticles were tunable by choosing the suitable chemical compositions of precursors, calcination temperatures, and the reducing gases during the gas-phase synthetic process. We have refined the existing fixed-bed activity test system by incorporating non-destructive infrared spectrometers for CH4 and CO2, which can be used to analyze the catalyst activity and stability of the metal/metal oxide catalysts.
The synthesized hybrid nanoparticles especially Cu-Ce-O NPs exhibited high activity, selectivity, high durability and operation stability, and ultra-low light-off temperatures in the catalysis. The Cu-Ce-O interfacial metal-support interaction promotes the redox cycle of surface oxidation of adsorbed methane and reduces coke formation, and we can depict the mechanisms catalyzed by CuCeOx-NP and CuO-NP.
We fabricate CuCeOx-NP and NiCeOx-NP hybrid nanoparticles with the controllable material properties by gas-phase two-stage synthetic reaction system for the applications in methane combustion and carbon dioxide reforming reaction. Results show that NiCeOx-NP hybrid nanoparticles are effective for CO2 reforming reaction due to the ability of CeO2 to release and adsorb oxygen from CO2 during the alternating redox conditions. CuxO-NP and CuCeOx-NP have been chosen as model materials to catalyze methane combustion. This work describes a prototype methodology of facile synthesis of nanocatalysts with well-controlled characteristics, which can be used to establish the correlation of material properties versus reducibility and subsequent catalytic activity for a variety of energy and environmental applications.

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