- 學位論文
利用開放式直流還原系統調控製程參數合成高效能奈米陽極觸媒應用於μDMFC
High Efficient Nanocatalyst Synthesis Using Open-Loop Flux Reduction System with Process Parameters Regulation in Micro DMFC
摘要
直接甲醇燃料電池(Direct Methanol Fuel Cell，DMFC)使用甲醇燃料，有高能量轉換效能，低污染，且可在低溫環境下操作等優點，與使用氫氣為燃料的質子交換膜燃料電池(Proton Exchange Membrane Fuel Cell，PEMFC)做比較，其燃料儲存較容易、室溫下即可操作且運作系統精簡。未來在攜帶式3C產品上的應用有著無限潛力。 本實驗使用平面Si為基材，鍍上Ni/Al/Ti薄膜做為碳管成長觸媒/電子傳導/黏著層。接著使用Thermal CVD成長奈米碳管增加乘載觸媒之表面積。成長後的碳管進行親水化處理，再利用本實驗室自製「開放式直流還原系統」乙二醇當作還原劑可在常壓下達到高溫觸媒還原[1]。然而，由於在此觸媒還原系統中溶液體積和反應溫度會隨著溶液蒸發與冷凝而改變，其提升沸點機制和傳統reflux系統不同，因此必須更進一步找出針對此自製觸媒還原系統最佳反應溫度與觸媒性能的關係。實驗結果顯示出能在較低還原溫度(130℃)有更佳的觸媒性能表現。後續利用相同方式找出純Ru還原最佳溫度參數(160℃)，最後嘗試還原PtRu。 目前研究最佳陽極觸媒製程為Ru(160℃)→Pt(130℃)→Pt:Ru=0.5:1(160℃)分三步順序還原PtRu。其成果CO毒化抑制能力較純Pt提升55% (Ipm/Ipco=0.83→1.29)，而質量活性較純Pt提升46% (506→739A/g)，已達近期化學還原文獻兩倍以上。未來將繼續進行PtRu二元合金觸媒製備，實際運用於本實驗室微型直接甲醇燃料電池全電池組裝研究。
並列摘要
Direct methanol fuel cell (DMFC) uses methanol as fuel, mainly because it has high energy conversion efficiency, low pollution, and it can operate at low temperature. Compared to proton exchange membrane fuel cell (PEMFC) using hydrogen gas as the anode fuel, DMFC has some advantages such as the safety of fuel storage, operation at room temperature, and so on. Therefore, DMFCs have potential applications for portable electronics. In this study, we use Si substrate, coated with Ni/Al/Ti film as carbon nanotube growth catalyst / electron transfer / adhesion layer. Then use the Thermal CVD growth carbon nanotubes to increase the surface area. After the growth of carbon tubes we use hydrophilic treatment, then use "Open-Loop Flux Chemical Reduction System" our lab design for Pt catalytic reduction. However, As the solution volume and temperature in the OLFCRS change with the solution evaporation/condensation process, the mechanism for enhancing the boiling point will be different from the traditional reflux system, so it is imperative to optimize the reaction temperature of Pt reduction in the OLFCRS. The results showed a lower reduction temperature (130℃) has better performance. Then we use the same method to find the best temperature reduction parameter of pure Ru (160℃). Finally we design PtRu reduction. Currently the best anode catalyst of the process is Ru (160℃)→Pt (130℃)→Pt: Ru = 0.5:1 (160℃) three steps. The results of CO poisoning enhance the inhibition 55% (Ipm/Ipco= 0.83→1.29) with pure Pt, and improve the quality of mass activity 46% (506→739A/g) with pure Pt. The result is double with the recent literature of chemical reduction. We will continue to research PtRu binary alloy catalyst preparation. Then practical application of the laboratory micro direct methanol fuel cell assembly of the whole cells.