劉如熹臺灣大學:化學研究所郭恆嘉Kuo, Heng-ChiaHeng-ChiaKuo2010-06-302018-07-102010-06-302018-07-102008U0001-2007200815090700http://ntur.lib.ntu.edu.tw//handle/246246/187423對於氫能經濟而言，目標之ㄧ即是用以取代汽油，成為運輸工具之最佳燃amp;#63934;。其中氫氣來源與貯氫材料開發乃為將氫能應用於運輸工具之關鍵技術。硼氫鈉乃為氫能經濟重要之材料，其可穩定存在鹼性水溶液二至三個月，氫氣重量度高達10.8 wt.%，可克服貯氫材料單位重量中氫氣含量過低之問題；亦可藉觸媒水解即時產生氫氣，克服氫氣輸出之問題，且可藉由特定觸媒提升氫氣生速率，故乃為極重要氫能經濟之材料。研究乃著重於硼氫化鈉產氫之奈米金屬/氧化物載體觸媒之合成與特性研，探討白金與各類金屬氧化物為載體合成觸媒對於硼氫化鈉產生氫氣速率之影。其中白金扮演傳導電子之角色；載體方面，易接受電子能力將大幅影響觸媒性；能力高者，如鈷之氧化物，觸媒活性極佳；能力低者，觸媒活性差。以鈷氧化物為載體之觸媒活性極高，然而經一次產氫後觸媒結構崩解，導致觸媒活大幅下降。而研究結果亦顯示可以鈷金屬為硼氫化鈉產氫觸媒，此舉將有助於發更經濟之硼氫化鈉燃料電池系統。研究藉由多種分析技術探討硼氫化鈉水解產氫反應特性與觸媒結構探。分析方法包括：以X光粉末繞射法(X-ray diffraction；XRD) 鑑定觸媒晶體結；以穿透式電子顯微鏡(transmission electron microscopy；TEM)進行樣品形貌粒徑大小分布分析；以X光吸收光譜(X-ray absorption spectroscopy；XAS)之X吸收邊緣結構(X-ray absorption near edge structure；XANES)鑑定樣品元素之價amp;#63849;與電子結構； 以感應耦合電漿原子發射光譜儀(inductively coupledlasma-atomic emission spectrometer；ICP-AES)鑑定白金含量。Hydrogen energy is being considered as an alternative energy source of the futureecause of its advantages in overcoming the ongoing energy crisis. A hydrogenconomy is proposed to solve the growing shortage of easily obtainable fossil fuel,nd global warming due to the emission of greenhouse gases to the atmosphere. Theost common challenge for hydrogen fuel economy is the storage of hydrogen andhemical hydrides are the best substitute of hydrogen storage system. One of the mostommonly used metal hydride is sodium borohydride, which has a storage density of0.8 wt % for hydrogen and can be used in combination to yield practical generationystem with proper engineering. The alkaline hydrolysis of sodium borohydride isccelerated by using a suitable catalyst such as platinum or ruthenium for achievingigher efficiencies for hydrogen generation. The objective of the present dissertations to study the role of different heterogeneous catalysts to produce hydrogen fromlkaline solutions of sodium borohydride and to understand the kinetics of hydrogeneneration. The Pt supported on Co3O4 (Pt/Co3O4) was synthesized by impregnationethod using H2PtCl6 as precursor for Pt and different ratio of Co3O4/CoO asrecursors for support. During the synthesis process, the polyol reduction was used toonfirm the oxidation of cobalt (II) oxide by H2PtCl6. It was observed that differentt/Co3O4 catalysts show better hydrogen generation efficiencies than the well knownt/LiCoO2 catalyst since platinum in Pt/Co3O4 has more 5d band vacancies. Theydrogen generation activity by using Pt/Co3O4 was decayed after first cycle,owever, it become stable after repeated cycles and can release hydrogen for longereriod. Among the different metal oxides used as a support, the cobalt oxide catalystas shown the best hydrogen generation activity since the catalyst has high electronccepting activity from sodium borohydride. These results are also supported by XRDeasurements of catalysts before and after the hydrogen generation.目錄.............................................................................................................................Ⅰ目錄..........................................................................................................................Ⅳ目錄..................................................................................................................... Ⅷ一章 緒論................................................................................................................1.1. 氫能之介紹....................................................................................................1.1.1. 石化能源之歷史........................................................................................1.1.2. 氫能經濟與氫能之重要性........................................................................2.2. 製氫技術簡介................................................................................................5.2.1. 光伏達電池(Photovoltaic Cell)分解水產氫3, 13-18...................................5.2.2. 太陽熱化學循環法(Solar Thermochemical Cycles)3, 19 ...........................6.2.3. 生物觀點產氫3 .........................................................................................7.3. 貯氫系統發展之研究....................................................................................8.3.1. 高壓貯氫方式............................................................................................9.3.2. 液化貯氫....................................................................................................9.3.3. 碳材料......................................................................................................10.3.3.1. 活性碳..............................................................................................10.3.3.2. 奈米碳纖維......................................................................................10.3.3.3. 奈米碳管..........................................................................................11.3.4. 金屬(合金)貯氫材料...............................................................................12.3.4.1. AB5 型：(A 代表稀土金屬、B 代表其他金屬)............................12.3.4.2. AB2 型..............................................................................................13.3.4.3. AB 型...............................................................................................13.3.4.4. A2B 型..............................................................................................13.3.5. 複合氫化物與化學氫貯氫材料..............................................................14.3.5.1. 複合氫化物與化學氫之特性與重要性研究..................................14.3.5.2. 複合氫化物貯氫材料......................................................................17.3.5.3. 化學氫貯氫材料與硼氫化鈉之重要性..........................................17.3.6. 綜合比較..................................................................................................19.4. 文獻回顧......................................................................................................20.5. 本研究目的..................................................................................................22二章 實驗步驟與儀器分析原理.........................................................................24.1. 化學藥品......................................................................................................24.2. 產氫觸媒製備方式與產氫實驗之配置......................................................25.2.1. 產氫觸媒製備方式..................................................................................25.2.2. 產氫實驗之配置......................................................................................27.3. 樣品之鑑定與分析......................................................................................28.3.1. X 光粉末繞射儀(X-ray Powder Diffractometer；XRD) ........................28.3.2. 同步輻射光源..........................................................................................31.3.3. X 光吸收光譜簡介..................................................................................32.3.4. 感應耦合電漿-原子發射光譜儀 (Inductively Coupled Plasma-Atomic Emission Spectrometer；ICP-AES).....................................................................34三章 結果與討論...................................................................................................39.1. 氧化鈷與四氧化三鈷為載體材料合成之觸媒研究..................................39.1.1. 金屬材料與金屬氧化物活性之研究......................................................39.1.2. 中科院提供鈷之氧化混合物載體材料觸媒之研究..............................41.1.3. 不同比例氧化鈷與四氧化三鈷為載體材料合成觸媒之研究..............47.1.3.1. 不同比例載體前驅物合成觸媒之晶體結構鑑定與機制之研究..47.1.3.2. 不同比例載體前驅物合成觸媒之活性研究..................................54.1.3.3. 多次產氫鉑-四氧化三鈷觸媒之研究............................................55.1.3.3.1. 多次產氫觸媒晶體結構分析......................................................55.1.3.3.2. 多次產氫觸媒之電子結構分析..................................................58.1.3.3.3. 多次產氫觸媒穿透式電子顯微鏡分析......................................62.1.3.3.4. 多次產氫觸媒產氫活性分析......................................................65.1.4. 鉑-四氧化三鈷(載體前驅物為四氧化三鈷)觸媒反應動力學研究.....67.1.4.1. 鉑-四氧化三鈷與四氧化三鈷動力學研究....................................67.1.4.2. 硼氫化鈉濃度之影響......................................................................69.1.4.3. 白金含浸量之動力學研究..............................................................70.1.5. 活性鉑-四氧化三鈷與鉑-鈷酸鋰觸媒產氫活性研究...........................71.1.5.1. 白金5d 能帶空缺對觸媒活性之影響............................................71.1.5.2. BET 表面積對觸媒活性之影響.....................................................74.2. 不同載體材料為前驅物合成之觸媒研究..................................................75.2.1. 各類觸媒產氫活性比較..........................................................................75.2.2. 各類觸媒之結構分析..............................................................................76.2.3. 觸媒活性之研究......................................................................................81.2.3.1. 白金含浸量之研究..........................................................................81.2.3.2. 觸媒載體接受電子難易之探討......................................................82.2.3.3. 中等活性觸媒之探討......................................................................83.2.3.4. BET 表面積之影響研究.................................................................84.2.3.5. 觸媒電性對催化活性之研究..........................................................85.2.3.6. 活性因素之結論..............................................................................85四章 結論...............................................................................................................86amp;#63851;考文獻.....................................................................................................................883870456 bytesapplication/pdfen-US硼氫化鈉產氫系統鉑-四氧化三鈷sodium borohydridehydrogen generationcatalystthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/187423/1/ntu-97-R95223003-1.pdf