| 摘要: | 隨著全球對潔淨能源的需求持續攀升，氫能因其高能量密度與零碳排放的特性，已成為實現能源轉型的關鍵選項。其中，電解水技術被廣泛視為綠氫生產的核心途徑。然而，水電解效率常受限於陰極析氫反應(hydrogen evolution reaction, HER)的動力學緩慢與陽極析氧反應(oxygen evolution reaction, OER)所需的高過電位。此外，酸性環境下催化劑的長期穩定性仍是一大挑戰。近年來，配對電解技術逐漸受到重視，該策略將陽極的氧氣析出反應改為有機物氧化反應(如乙醇氧化反應ethanol oxidation reaction, EOR)，不僅能有效降低系統能耗，亦可同時產出氫氣與高附加值化學品。
本研究以水熱法合成了具高貴金屬利用率的Pd基催化劑，並透過二維結構的設計與Pt的摻雜，有效調控其電子結構，以提升催化活性與結構穩定性。在HER反應中，PdMo-Pt3展現出極低的過電位(21 mV)、Tafel斜率(14 mV dec-1)與高質量活性(2189 A gPd(+Pt)-1)，並在經過10,000次加速耐久性測試後仍維持穩定表現。於EOR反應中，PdMo-Pt2則展現出最高的質量活性(7239 A gPd(+Pt)-1)與最大的電化學活性表面積(93 m² gPd(+Pt)-1)，顯示其優異的雙功能催化性能。進一步應用於配對電解系統時，該催化劑可同時促進HER與EOR反應，不僅顯著降低整體能耗，亦能同步產生氫氣與高附加值有機產物。
此外，本研究亦透過原位X光吸收光譜(in-situ X-ray absorption spectroscopy, in-situ XAS)與感應耦合電漿放射光譜(inductively coupled plasma optical emission, ICP-OES)，深入探討催化劑在HER反應下的穩定性機制。XAS結果顯示，Pt的摻雜不僅作為反應活性位點，也有助於提升整體結構穩定性；而ICP-OES分析則進一步證實，Pt的引入能有效抑制Pd在酸性電解液中的溶解，顯著增強其耐腐蝕能力。
綜合而言，本研究所提出具前瞻性的設計策略以開發具有優異HER與EOR性能的PdMo-Pt雙功能催化劑，對於推動綠氫技術與節能水分解系統具有重要應用價值。
;With the increasing global demand for clean energy, hydrogen has emerged as a key solution in the transition toward sustainable energy systems, due to its high energy density and zero carbon emissions. Among various hydrogen production methods, water electrolysis is considered a core technology for generating green hydrogen. However, the overall energy efficiency is constrained by the sluggish kinetics of the HER at the cathode and the high overpotentials required for the OER at the anode. Moreover, in acidic environments, the long-term durability of catalysts poses an additional challenge. In recent years, paired electrolysis has attracted growing interest as a promising strategy to reduce energy consumption by replacing the anodic OER with the oxidation of organic compounds, such as the EOR, thereby enabling the co-production of hydrogen and value-added chemicals.
In this study, palladium (Pd)-based catalysts with high noble metal utilization were synthesized via a hydrothermal method. A two-dimensional (2D) structure was constructed, and platinum (Pt) was incorporated to modulate the electronic structure of the catalysts, resulting in enhanced catalytic activity and structural stability. In acidic electrolytes, the PdMo-Pt3 catalyst exhibited an ultralow overpotential (21 mV), a small Tafel slope (14 mV dec-1), and a high mass activity (2189 A gPd(+Pt)-1), while maintaining excellent performance after 10,000 cycles of accelerated durability tests (ADT). For EOR, PdMo-Pt2 achieved the highest mass activity (7239 A gPd(+Pt)-1) and the largest electrochemical surface area (93 m² gPd(+Pt)-1), highlighting its outstanding bifunctional performance. When applied in a paired electrolysis system, the catalysts effectively coupled HER and EOR, significantly lowering overall energy consumption and enabling the simultaneous production of hydrogen and organic products.
Furthermore, the mechanism of HER stability was investigated through in-situ X-ray absorption spectroscopy (XAS) and inductively coupled plasma optical emission spectroscopy (ICP-OES). XAS results revealed that Pt incorporation enhanced catalyst stability by serving as active sites, while ICP-OES confirmed that Pt doping suppressed Pd dissolution, leading to improved corrosion resistance under acidic conditions.
Overall, this study demonstrates a promising strategy for the design of high-performance bifunctional electrocatalysts and provides valuable insights into the development of energy-efficient and economically viable water splitting systems. |
