本研究以非恆溫沉澱法製備針狀CeO2擔體，再以微濕含浸法擔載Ag或Pt，製備出Ag/N-CeO2、Pt/N-CeO2以及Ag-Pt/N-CeO2觸媒，並進行CO氧化反應。本文探討變因有三，一為微濕含浸法中是否使用磁石攪拌，二為以依序含浸法及共含浸法製備Ag-Pt/N-CeO2，三為Ag與Pt之擔載濃度，探討上述變因對各觸媒形態、粒徑、晶相結構等特性之影響，並輔以TPR、in-situ FTIR及XPS分析，解析Ag、Pt與CeO2間之交互作用。
實驗結果顯示，使用磁石攪拌會使得N-CeO2長度變短，且粒子間之孔徑變小，造成比表面積下降，觸媒之催化活性亦下降。共含浸法經歷一次煅燒，降低粒子間聚集的機率，但結晶度亦會下降。因Pt-O-Ce鍵之生成，Pt較Ag有更佳之分散度，粒徑也較Ag小，由XRD與HRTEM結果發現Pt結晶度優於Ag，皆為Pt/N-CeO2活性優於Ag/N-CeO2之原因。此外，由in-situ FTIR及XPS結果發現，Ag將部分電子轉移至Ce上使得CeO2氧空缺增加，提高催化活性；Pt則接收Ce轉移之電子，使表面帶較多負電荷，更易吸附CO分子，由此提高觸媒活性。
室溫(30oC)下，擔載低濃度(0.03%、0.05%及0.1%)之金屬含量，共含浸之Ag-Pt/N-CeO2擁有最佳催化活性(轉化率5-8%)，提高金屬含量至0.5%時，以依序含浸之Ag-Pt/N-CeO2催化活性最高(轉化率72.94%)，當金屬擔載量提高時，僅共含浸之Ag-Pt/N-CeO2未有明顯活性改善，推測係因共含浸法可能形成合金，當擔載高濃度之雙金屬時，Ag的存在降低Pt吸附CO之能力，而依序含浸法有較好之活性推測為Ag-Pt間之電子轉移，加上金屬與擔體間之協同作用所致。

Silver and platinum nanoparticles loaded on ceria needles synthesized by incipient wetness impregnation were employed as CO oxidative catalysts. Properties of catalysts including morphologies, particle size, crystalline structure and interactions between Ag, Pt and ceria are characterized by using TEM, HRTEM, XRD, TPR, in-situ FTIR and XPS analysis. From the experimental results, stirring with the stirring bar in impregnation process decreased the length the void size of ceria support. For the bimetal catalysts, the dispersion is better while the crystallinity is worse by the co-impregnation method. As different metal loaded on the support, Pt has better crystallinity and smaller size than Ag because of the Pt-O-Ce bonds. Moreover, it is found that the transfer of electrons from Ag to Ce increases the oxygen vacancy of CeO2 and improves the catalytic activity. The transfer of electrons from Ce to Pt makes the surface more negatively charged and easier to adsorb CO molecules. Ag-Pt/N-CeO2 catalysts which loaded low concentration of metal(0.03, 0.05 and 0.1%) by co-impregnation method show the highest activity on CO oxidation at the room temperature. Ag-Pt/N-CeO2 catalysts which loaded higher concentration of metal(0.5%) by sequential impregnation method show the highest activity on CO oxidation at the room temperature. This is attributed from the transfer of electrons and synergistic effect of metal-support.

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