| 摘要: | 現今，鉑基觸媒被視為析氫反應(hydrogen evolution reaction, HER)的基準，因為它們在0到14的pH值範圍內表現出出色的活性。然而，高成本，穩定性差以及貴金屬的稀有性限制了它們的廣泛應用。另一方面，未來低碳能源系統的潛在候選人，氫氣，卻大部分均來自蒸汽重整，亦會產生二氧化碳，造成全球暖化。因此，設計低鉑含量且高原子利用率觸媒為實際應用的重要課題。本研究利用改變冷凍光還原法的照光時間，並同時添加第二金屬前驅物，達到一步驟合成雙金屬奈米團簇觸媒。透過旋轉圓盤電極（RDE），分析了低負載量之鉑基奈米觸媒的HER活性，利用感應耦合電漿原子發射光譜儀(Inductively Coupled Plasma Optical Emission Spectrometry, ICP-OES）、X光繞射儀(X-ray Diffractometer, XRD)、高解析穿透式電子顯微鏡(High-Resolution Transmission Electron Microscopy, HRTEM)以及X射線光電子能譜儀(X-ray Photoelectron Spectroscopy, XPS)，去分析化學組成、結構、形貌和表面組成。
透過HRTEM觀察到經由還原時間的縮減，得到金屬尺寸的縮小，並形成單金屬和雙金屬奈米團簇觸媒。而本研究中雙金屬奈米團簇之觸媒PtPd-A，在HER性能與穩定性為最佳樣品。有最低之Tafel斜率18 mV/dec.、在10 mA / cm2之過電勢(η10)為39 mV，以及最高的質量活性(Mass activity, MA)9.09 A/mg。即使在計時安培分析法(Chronoamperometry Analysis, CA)6小時測試後，不只在Tafel斜率和η10維持不變，並有在MA上仍保持6.17 A/mg的高質量活性。
;Nowadays, platinum-based catalysts are regarded as the benchmark for hydrogen evolution reaction (HER) because they show excellent activity in the pH range of 0 to 14. However, high cost, poor stability, and the rarity of precious metals limit their widespread use. On the other hand, potential resources for low-carbon energy systems in the future, hydrogen, are produced from steam reforming, which results in CO2 emission and causes global warming. Therefore, designing a catalyst with low platinum content and high atomic utilization efficiency is an important topic for practical applications. In this study, iced photochemical reduction with different irradiation time are used, and the second metal precursor are added at the same time to achieve the one-step synthesis of the bimetallic nanocluster catalyst. The rotating disk electrode (RDE) was used to analyze the HER activity of the platinum-based nanocatalyst with low loading. The inductively coupled plasma atomic emission spectrometry (ICP-OES) and X-ray diffraction were used. X-ray Diffractometer (XRD), high-resolution transmission electron microscopy (HRTEM), and X-ray photoelectron spectroscopy (XPS) were used to analyze chemical composition and structure, Morphology, and surface composition of the catalysts, respectively. HRTEM results suggest that when the reduction time is reduced, the size of the metal is reduced, Among all sampes, the best one is the PtPd-A bimetallic nanoclusters which has the lowest Tafel slope of 18 mV/dec., the overpotential (η10) at 10 mA/cm2 is 39 mV, and the highest mass activity (mass activity, MA)of 9.09 A/mg. Even after 6 hours of chronoamperometry analysis (CA) test, not only the Tafel slope and η10 remain unchanged, but also a high MA 6.17 A/mg is achieved. |
