常壓噴射電漿表面改質提升陰離子交換膜水電解系統中鎳鉬氧化物/碳紙複合電催化劑之析氧反應活性

Abstract

隨著再生能源的快速發展，氫氣作為潔淨能源在儲能與轉換應用上扮演關鍵角色。其中，水電解產氫技術因其成本較低且操作穩定，被視為實現綠色氫能的重要技術。然而，析氧反應(Oxygen Evolution Reaction, OER)在電解水中具有較高的動力學障礙，限制了整體能量轉換效率。為解決此問題，本研究提出一種以鎳鉬氧化物(NiMoO4)為基礎的非貴金屬電極材料，並結合常壓噴射電漿（Atmospheric-Pressure Plasma Jet, APPJ）進行表面改質，以提升其OER活性與電化學穩定性。 鎳鉬氧化物首先以水熱法合成並原位生長於碳紙(Carbon Paper, CP)基材上，形成良好的結構。接著透過APPJ快速高溫處理60秒，成功引入表面氧缺陷與活性位點，改善材料的導電性與電化學反應活性。經電化學測試，處理後之NiMoO4/CP/APPJ-60 s電極在100 mA/cm2電流密度下，其過電位由處理前的大於879 mV降至790 mV，顯示出良好的OER性能。同時，其電荷轉移電阻由2.8 Ω顯著下降至1.2 Ω，證明APPJ處理可有效促進電子傳輸並降低反應阻力。 進一步將此電極應用於陰離子交換膜水電解(Anion Exchange Membrane Water Electrolysis, AEMWE)系統，於70°C操作下達到95.1%之能量效率，且比能耗由4.02 kWh/m3降至3.83 kWh/m3，展現出優異的系統性能與節能潛力。整體而言，本研究所提出之NiMoO4/CP/APPJ電極不僅展現OER活性與穩定性，也具備可擴展性與環境友善特性，有望作為貴金屬催化劑之替代材料，為未來高效、低成本的水電解系統提供新的想法

Hydrogen is regarded as a clean and sustainable energy carrier, and water electrolysis is one of the most promising technologies for green hydrogen production. However, the oxygen evolution reaction (OER) involved in the process is hindered by sluggish kinetics, limiting the overall system efficiency. To address this challenge, a non-precious metal electrode based on nickel molybdate (NiMoO4) was synthesized on carbon paper (CP) via a hydrothermal method. An atmospheric-pressure plasma jet (APPJ) treatment was applied for 60 s to introduce surface oxygen vacancies and active sites, enhancing the material’s conductivity and catalytic activity. The APPJ-treated NiMoO4/CP electrode exhibited a reduced overpotential of 790 mV at 100 mA/cm2, along with a significant drop in charge transfer resistance from 2.8 Ω to 1.2 Ω. When integrated into an anion exchange membrane water electrolysis (AEMWE) system operating at 70°C, the electrode achieved 95.1% energy efficiency, and the specific energy consumption decreased from 4.02 to 3.83 kWh/m3. These findings demonstrate that APPJ modification effectively improves OER performance and system energy efficiency. The developed NiMoO4-based electrode offers a scalable, low-cost, and environmentally friendly alternative to precious metal catalysts, holding strong potential for practical applications in advanced water electrolysis systems