電解水製氫是再生能源轉化與利用的重要途徑，其中陰極析氫反應的動力學過程直接影響製氫效率與能耗。Pt 基催化劑雖然具有優異的析氫活性，但其成本高、資源受限，難以滿足大規模應用需求。金屬有機骨架材料具有組成可調、配位環境明確和結構可設計等特點，在非貴金屬析氫催化劑研究中受到持續關注。已有關於共軛配體調控作用的認識主要來自二維共軛金屬有機骨架 (Metal-organic framework, MOF) 體系，相關研究指出，平面 π 共軛骨架的擴展有利於提高 π 電子未定域化程度，並改善電子傳輸。相比之下，在金屬中心局部配位環境基本一致的條件下，配體共軛面積變化對 MOF 析氫反應性能與動力學參數的影響仍缺少系統比較。基於此，選取 PMDA、NTDA 和 PTCDA 三種芳香骨架依次擴展的四羧酸酐前驅體作為配體，經水解後分別與 Ni2+ 和 Co2+ 組裝，建立兩組對應的 MOF 催化劑，用以研究配體共軛面積對骨架電子結構、介面電荷轉移、質傳行為及析氫動力學的影響。
鑑定結果證實 Ni–PMDA、Ni–NTDA、Ni–PTCDA 及對應的 Co 基樣品均成功形成 MOF。粉末 X 光繞射和傅利葉轉換紅外光譜結果顯示，所得材料具有良好的結晶性，並且配體以羧酸鹽形式與金屬中心形成配位結構。掃描電子顯微鏡與能量色散 X 光譜結果表明，各樣品呈現片狀或層狀堆疊形貌，且元素分佈較為均勻。X 光光電子能譜分析進一步顯示，Ni 基樣品中 Ni 主要以 +2 價存在，Co 基樣品中呈現 Co3+/Co2+ 共存特徵；同時，金屬 2p 結合能由 PMDA、NTDA 到 PTCDA 呈下降趨勢，說明當配體共軛程度提高時，金屬中心附近電子雲密度相應增加。上述結果說明，各樣品在局部配位環境上具有較好的可比性，為後續討論配體共軛面積變化與析氫反應性能差異之間的關係提供了結構基礎。
電化學測試表明，擴大配體共軛面積能夠改善 MOF 催化劑在酸性介質中的析氫反應性能。以 Ni 基體系為例，在 0.5 M H2SO4 中，從 Ni–PMDA、Ni–NTDA 到 Ni–PTCDA 的析氫反應性能增強。在 100 mA cm−2 電流密度下，三者的過電位分別為 478、464 和 448 mV，對應的 Tafel 斜率分別為 62.35、58.51 和 52.61 mV dec−1；隨著電流密度進一步提高，三者之間的性能差異更加明顯。Nyquist 圖和 Bode 圖結果進一步指出，由 Ni–PMDA、Ni–NTDA 到 Ni–PTCDA，樣品的電荷轉移電阻降低，低頻區質傳相關阻抗也減小，質傳限制相應減弱；雙電層電容結果則說明樣品電化學活性面積逐步增大。Co 基體系呈現與 Ni 基體系一致的變化趨勢。重複性測試進一步表明，不同樣品之間的性能差異具有良好的再現性。
為研究上述規律是否可推廣至其他金屬中心，本研究進一步建立了對應的 Cu–MOF 體系進行補充驗證。結果顯示，Cu–PMDA、Cu–NTDA 和 Cu–PTCDA 同樣成功形成對應 MOF 結構，並表現出與 Ni 基和 Co 基體系一致的活性變化順序。隨著配體共軛面積從 PMDA、NTDA 增加到 PTCDA，Cu 基樣品的電荷轉移電阻降低，低頻區質傳相關阻抗減小，析氫反應過電位與 Tafel 斜率均下降。綜合 Ni 基、Co 基與 Cu 基三組 MOF 體系的結果可知，配體共軛面積調控對 MOF 析氫反應性能的影響具有一定的通用性。
綜上所述，用 PMDA、NTDA 和 PTCDA 三種配體建立的 MOF 體系進行比較，結果表明配體共軛面積增大能夠同時降低介面電荷轉移電阻和質傳限制，並改善 MOF 的析氫反應動力學。本研究將二維共軛 MOF 研究中擴大配體 π 共軛範圍有助於促進電子傳輸的結論，進一步延伸到這類三維過渡金屬 MOF 催化體系，並表明透過共軛配體工程改善骨架電子傳輸、促進介面電荷轉移，並減弱質傳限制，是提升 MOF 催化性能的一條可行策略。對於其他同樣涉及載流子傳導與質傳限制的 MOF 電催化、光催化及相關應用體系，此策略可為有機配體設計與傳輸過程調控提供參考。

Metal-organic frameworks (MOFs) combine permanent porosity with highly tunable compositions, periodically ordered structures, and well-defined coordination environments, thereby offering versatile electrocatalyst platforms. Although ligand engineering has been widely explored to improve MOF-based hydrogen evolution reaction (HER) catalysis, the catalytic role of ligand π-conjugation area remains unclear. In particular, few studies have treated π-conjugation area as a defined molecular variable to examine its influence on interfacial HER kinetics. Here, conjugated-ligand engineering denotes the systematic use of ligands with different π-conjugation areas to modulate MOF electrocatalytic behavior while largely preserving comparable metal coordination environments. Three aromatic ligands—pyromellitic dianhydride (PMDA), naphthalene-1,4,5,8-tetracarboxylic dianhydride (NTDA), and perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA)—are employed to construct homologous MOFs with six-coordinate metal centers (M = Ni, Co). Expanding the ligand π-conjugation area from PMDA to PTCDA lowers overpotentials and Tafel slopes, reduces charge-transfer resistance, increases electrochemical active surface area, and lowers low-frequency impedance. These correlated electrochemical responses indicate that ligand π-extension can influence transport-related electrochemical behavior and interfacial HER kinetics. This work highlights ligand π-conjugation area as a molecular design parameter for MOF electrocatalysts and provides a structure-kinetics perspective for conjugated-ligand engineering in HER.

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