自發性生物質分子氧化反應之研究

Abstract

異位性皮膚炎為常見之慢性發炎性皮膚疾病，其致病原因與皮膚屏障功能異常、免疫失調及環境因子有關，近年全球病例數增加，使相關治療需求受到重視，目前外用皮質類固醇為異位性皮膚炎常見之治療方式，其中莫米松糠酸酯為具代表性之藥物之一，而糠酸可作為其糠酸酯結構之前驅物，顯示糠酸於醫藥分子合成中具有應用價值，然而，傳統糠酸合成途徑常面臨反應條件嚴苛、成本較高、副產物生成以及反應時間較長等問題，限制其高選擇性與高效率製備，因此，電化學催化逐漸成為合成糠酸之替代策略。 目前多數研究於鹼性條件下，藉由施加偏壓將糠醛(furfural; FF)氧化為糠酸(furoic acid; FAD)，但鹼性溶液會使糠醛分子發生歧化反應和自聚合等副反應；同時陰極還原反應亦可能影響糠醛氧化反應表現，為改善上述限制，本研究引入氧化還原儲庫(redox reservoir; RR)概念，藉由氫氧化鎳RR電極之可逆氧化還原特性，將氧化與還原反應解耦，並因應不同目標反應調控操作環境，此外，氫氧化鎳RR電極亦能於無施加偏壓且無電解質的條件下，自發驅動糠醛氧化反應，擺脫鹼性狀況之束縛，解決直接電催化所面臨的副反應問題。 為提高氫氧化鎳RR電極反應活性，本研究引入鈷修飾氫氧化鎳RR電極，以提升其催化效能，並應用於高濃度糠醛氧化反應，除了糠醛以外，氫氧化鎳RR電極亦可作為不同取代基之苯甲醛氧化媒介，以比較不同醛類分子之間反應速率。此外，本研究也探討二氧化碳還原反應(carbon dioxide reduction reaction; CO2RR)，實現90 %以上的糠酸產率與100 % 左右的CO2RR產物總法拉第效率，擴展氫氧化鎳RR電極於解耦催化與成對電解系統中之應用潛力。

Atopic dermatitis is a common chronic inflammatory skin disease associated with barrier dysfunction, immune dysregulation, and environmental factors, and its global prevalence is increasing. Mometasone furoate contains a furoate moiety for which furoic acid (FAD) can serve as a precursor. However, conventional FAD synthesis involves harsh conditions, high costs, byproducts, and long reaction times. Therefore, electrocatalysis offers an alternative. Most studies oxidize furfural (FF) to FAD under alkaline conditions with an applied bias. However, alkaline media induce FF disproportionation and self-polymerization, while cathodic reactions may also affect oxidation performance. To address these limitations, this study introduces a nickel hydroxide redox reservoir (RR) electrode, whose reversible redox properties decouple oxidation and reduction and allow the environment to be tailored to each reaction. The nickel hydroxide RR electrode spontaneously drives furfural oxidation without applied bias or electrolyte, avoiding alkaline conditions and mitigating side reactions in direct electrocatalysis. To enhance activity, cobalt-modified nickel hydroxide RR electrodes were developed for high-concentration furfural oxidation. The nickel hydroxide RR electrode also mediated oxidation of differently substituted benzaldehydes, enabling comparison of reaction rates. Carbon dioxide reduction reaction (CO2RR) was further investigated, achieving over 90% FAD yield and approximately 100% total faradaic efficiency for CO2RR products. These results highlight the potential of nickel hydroxide RR electrodes in decoupled catalysis and paired electrolysis.