| DC 欄位 |
值 |
語言 |
| DC.contributor | 材料科學與工程研究所 | zh_TW |
| DC.creator | 蘇柏誠 | zh_TW |
| DC.creator | Pai-Cheng Su | en_US |
| dc.date.accessioned | 2013-3-26T07:39:07Z | |
| dc.date.available | 2013-3-26T07:39:07Z | |
| dc.date.issued | 2013 | |
| dc.identifier.uri | http://ir.lib.ncu.edu.tw:88/thesis/view_etd.asp?URN=100329002 | |
| dc.contributor.department | 材料科學與工程研究所 | zh_TW |
| DC.description | 國立中央大學 | zh_TW |
| DC.description | National Central University | en_US |
| dc.description.abstract | 本研究系統性的探討鈀觸媒(Pd/C)藉由金和鎳的添加，所形成二元和三元(Pd3Au/C, Pd3Ni/C和Pd3AuNi/C)觸媒之鹼性環境下乙醇氧化反應。所製備觸媒的金屬含量、乙醇氧化活性、結構、形貌、表面組成和表面物種可由熱重分析儀和感應耦合電漿原子發射光譜分析儀、循環伏安法、X光繞射分析儀和X光吸收能譜儀、高解析穿透式電子顯微鏡、X光電子能譜儀和程溫還原系統分析。
觸媒表面以氫氧化氧物形式所存在的鎳可以因雙功能機制(bi-functional mechanism)和溢流效應(spillover effect)來促進鈀觸媒之乙醇氧化反應的進行，而觸媒中的金可修飾鈀的晶格和電子結構以促進乙醇分子的吸附。根據常溫下計時伏安法的結果，鈀金鎳觸媒在四小時乙醇氧化反應後的質量電流密度為鈀和鈀金觸媒之1.39和1.10倍，此鈀金鎳觸媒穩定性的提升乃歸因於金和鎳的合金化增益效應。
為了進一步增進鈀金鎳觸媒的乙醇氧化能力，以電化學去合金法(dealloying)和熱處理法改質。鈀金鎳觸媒在去合金化、一氧化碳和氧氣熱處理後的乙醇氧化能力下降。而在560 K氫氣熱處理或還原後的鈀金鎳觸媒，在兩小時乙醇氧化反應後，其質量電流密度各為鈀金鎳觸媒的1.16和1.41倍，此乃歸因於表面鈀的含量和表面金屬態鈀的增加。因此適當的表面組成和表面金屬態對於提升鈀金鎳觸媒的穩定性為一非常重要的因素。 | zh_TW |
| dc.description.abstract | The effect of Au and/or Ni addition on the ethanol oxidation reaction (EOR) performance in alkaline media of Pd based binary and ternary catalysts (Pd3Au/C, Pd3Ni/C, and Pd3AuNi/C) is systematically elucidated. The metal loading, EOR activities, structures, morphologies, surface compositions and surface species of the prepared catalysts are analyzed by the thermal gravimetric analysis (TGA) and inductively coupled plasma-atomic emission spectrometer (ICP-AES), cyclic voltammetry (CV), X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS), high resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS) and temperature-programmed reduction (TPR), respectively.
It is observed that the surface Ni with the chemical state of NiOOH can promote the EOR through bi-functional mechanism and spillover effect while surface Au can modify the Pd lattice and electron configuration which is helpful for the absorption of ethanol molecular. Chronoamperometric (CA) results obtained at room temperature demonstrate that the mass current density of ternary Pd3AuNi/C catalysts after the long-term EOR test for 4 h is about 1.39 and 1.10 times higher than that of the monometallic Pd/C and binary Pd3Au/C catalysts, respectively. It is proposed that the enhancement in EOR stability of Pd3AuNi can be attributed to the synergistic effect of Ni and Au alloying.
The Pd3AuNi catalysts are then further modified by electrochemical dealloying or heat treatment processes in order to promote their EOR performance. The dealloying process or heat treatment at CO or O2 do not have positive effect on the EOR activity of the Pd3AuNi catalysts. For the Pd3AuNi catalysts heat-treated and reduced in H2 at 560 K, after CA test of 2 hours, the mass current density is about 1.16 and 1.41 times higher than that of the as-prepared Pd3AuNi catalysts. This result is attributed to the increase in surface Pd content and metallic states after the heat treatment or reduction in H2 at 560 K. Therefore, the proper surface composition and chemical states are essential for the improvement in the stability of Pd3AuNi catalysts. | en_US |
| DC.subject | 鈀金鎳觸媒 | zh_TW |
| DC.subject | 乙醇氧化反應 | zh_TW |
| DC.subject | 鹼性溶液 | zh_TW |
| DC.subject | 長時間穩定性 | zh_TW |
| DC.subject | X光吸收能譜儀 | zh_TW |
| DC.subject | 程溫還原系統 | zh_TW |
| DC.subject | 去合金 | zh_TW |
| DC.subject | 熱處理 | zh_TW |
| DC.subject | PdAuNi catalysts | en_US |
| DC.subject | ethanol oxidation reaction (EOR) | en_US |
| DC.subject | alkaline solution | en_US |
| DC.subject | long-term stability | en_US |
| DC.subject | X-ray absorption spectroscopy (XAS) | en_US |
| DC.subject | temperature-programmed reduction (TPR) | en_US |
| DC.subject | dealloying | en_US |
| DC.subject | heat-treatment | en_US |
| DC.title | 鈀金鎳觸媒在鹼性乙醇氧化環境下結構與活性的關係 | zh_TW |
| dc.language.iso | zh-TW | zh-TW |
| DC.title | The Structure-Activity Relationship of Carbon-Supported Pd3AuNi Catalysts for Ethanol Oxidation Reaction in Alkaline Solution | en_US |
| DC.type | 博碩士論文 | zh_TW |
| DC.type | thesis | en_US |
| DC.publisher | National Central University | en_US |