近日，我校化學與化工學院曹麗慧教授團隊圍繞離子型氫鍵有機框架（iHOFs）材料的質子傳導及燃料電池應用開展了一系列研究工作，在Advanced Functional Materials（IF = 18.5）、Chemical Engineering Journal（IF = 13.3）、ACS Materials Letters（IF = 9.6）期刊上發表了三篇研究論文，并受邀撰寫電荷輔助iHOFs材料的設計合成及應用的相關綜述（Chemistry-A European Journal, 2024, 30, e202303580）。

氫鍵有機框架（HOFs）是由有機分子單元通過非共價氫鍵相互作用構建而成的晶體，分子間作用力較弱，因此合成和設計具有超質子傳導性和穩健性的氫鍵有機框架相對困難。通過酸堿配對策略自組裝的離子氫鍵有機框架（iHOFs），由于具有豐富的氫鍵、強離子鍵以及π-π堆積等相互作用使之成為可能，結構中豐富的氫鍵為質子提供了獨特的輸運路徑。同時，iHOFs中的酸堿有機分子可作為質子載體或質子源，有效地傳輸質子，可獲得具有超質子導電性的材料。

本文利用聯苯二磷酸和1,1’-二氨基-4,4’-二聯吡啶為原料制備了一例大尺寸的三維（3D）氫鍵網絡結構iHOF-16，該材料具有優異的熱穩定性和化學穩定性，在強酸堿條件下也能保持高結晶度和堅固的結構。iHOF-16沿a軸、b軸和c軸方向分別具有0.388、5.56×10^-3和3.25×10^-4 S cm^-1的高各向異性質子傳導率。利用密度泛函理論（DFT）計算結果表明質子最容易在a軸方向傳輸，從而產生超質子傳導率。通過電荷輔助合成策略，為設計穩定的超質子導電材料提供了一種可行的方法。

相關成果以“An Ultra-Robust and 3D Proton Transport Pathways iHOF with Single-Crystal Superprotonic Conductivity Around 0.4 S·cm^?1”為題，發表在Advanced Functional Materials（IF = 18.5）上。陜西科技大學為論文第一通訊單位，化學與化工學院2023級博士研究生曹蕭杰為該論文的第一作者，曹麗慧教授為第二作者和論文唯一通訊作者。

本工作以1,3,5-三（4-膦酸基苯基）苯與鹽酸胍為原料，在二甲胺調節的作用下，成功制備了兩種iHOFs（即iHOF-14、iHOF-15）。其中，胍陽離子和芳基膦酸陰離子通過電荷輔助氫鍵增強了框架的穩定性。由于豐富的氫鍵網絡，iHOF-14和iHOF-15表現出超過10^-2 S·cm^-1的質子導電性。此外，我們將iHOFs摻雜到Nafion基質中，得到了具有更豐富的質子傳輸路徑和良好的甲醇阻隔性能的PEM。在100 °C和98% RH下，9%-iHOF-14/Nafion和9%-iHOF-15/Nafion電導率分別達到1.53 × 10^-1和1.78 × 10^-1 S·cm^-1。72 h的甲醇滲透實驗結果表明，復合膜的甲醇滲透率比重鑄后的Nafion低73.7%。用于DMFCs的混合膜的最大功率密度約為80 mW·cm^-2，是重鑄Nafion的1.5倍。這一工作不僅豐富了芳基膦酸鹽iHOFs，而且拓展了用于DMFC的iHOFs/Nafion PEM材料。

相關成果以“Dimethylamine-tuned guanidinium arylphosphonate iHOFs and superprotonic conduction Nafion hybrid membranes for DMFCs”為題，發表在Chemical Engineering Journal（IF = 13.3）上。陜西科技大學為論文唯一通訊單位，化學與化工學院2022級博士研究生白向田為該論文的第一作者，曹麗慧教授為論文唯一通訊作者。

本文以六(4-磺酸基苯基)苯和1,1’-二氨基-4,4’-二聯吡啶為原料合成了具有三維氫鍵網絡的iHOF-13。穩定的iHOF是通過電荷輔助氫鍵相互作用連接，并通過靜電吸引進一步加強。同時，結晶水分子的存在促進了更廣泛的氫鍵網絡形成，從而使iHOFs具有超質子導電性。具體來說，iHOF-13在98% RH和100 °C下的質子電導率為1.3 × 10^-1 S·cm^-1。iHOF富含質子輸運位點，其摻雜到Nafion基體中表現出極高的質子電導率（10^-1 S·cm^-1）和低的甲醇滲透率。在直接甲醇燃料電池中，7.5%-iHOF-13/Nafion復合膜的最大功率密度可達104.7 mW·cm^-2，是重鑄Nafion的2.1倍。高性能iHOF的加入有助于增強質子傳輸途徑，同時有效抑制甲醇交叉，從而擴大其在燃料電池中的潛在應用。

相關成果以“Arylsulfonate Ionic Hydrogen-Bonded Organic Frameworks Enable Highly Stable and Superprotonic Conductivity for Enhancing Direct Methanol Fuel Cells” 為題，發表在ACS Materials Letters上（IF = 9.6）上。陜西科技大學為論文唯一通訊單位，化學與化工學院2022級博士研究生白向田為該論文的第一作者，曹麗慧教授為論文唯一通訊作者。

以上研究成果得到國家自然科學基金（22075169）和陜西基礎科學（化學、生物學）研究院科學研究計劃項目（22JHQ026）的支持。

原文鏈接：https://doi.org/10.1002/adfm.202409359

https://doi.org/10.1016/j.cej.2024.150747

https://doi.org/10.1021/acsmaterialslett.4c00953

https://doi.org/10.1002/chem.202303580

新聞小貼士：

附：曹麗慧教授團隊近三年代表性論文：

1. X.-J. Cao, L.-H. Cao*, X.-T. Bai, X.-Y. Hou, H.-Y. Li, An Ultra-Robust and 3D Proton Transport Pathways iHOF with Single Crystal Superprotonic Conductivity Around 0.4 S·cm^?1, Adv. Funct. Mater., 2024, 2409359. (IF₂₀₂₃=18.5)

https://doi.org/10.1002/adfm.202409359

2. X.-T. Bai, L.-H. Cao*, X.-Y. Chen, S.-H. Li, J.-H. Zhang, Dimethylamine-tuned guanidinium arylphosphonate iHOFs and superprotonic conduction Nafion hybrid membranes for DMFCs, Chem. Eng. J., 2024, 487, 150747. (IF₂₀₂₃=13.3)

https://doi.org/10.1016/j.cej.2024.150747

3. X.-T. Bai, L.-H. Cao*, F. Zhao, and S.-H. Li, Arylsulfonate Ionic Hydrogen-Bonded Organic Frameworks Enable Highly Stable and Superprotonic Conductivity for Enhancing Direct Methanol Fuel Cells, ACS Materials Lett., 2024, 6, 3351?3357. (IF₂₀₂₃=9.6)

https://doi.org/10.1021/acsmaterialslett.4c00953

4. M.-F. Huang, L.-H. Cao*, and B. Zhou, A solvent-controlled photoresponsive ionic hydrogen-bonded organic framework for encryption applications, Chem. Commun., 2024, 60, 3437–3440. (IF₂₀₂₃=4.3)

https://doi.org/10.1039/D4CC00701H

5. X.-Y. Chen, L.-H.Cao*, X.-T. Bai, and X.-J. Cao, Charge-Assisted Ionic Hydrogen-Bonded Organic Frameworks: Designable and Stabilized Multifunctional Materials, Chem. Eur. J., 2024, 30, e202303580. (Invited Review, IF₂₀₂₃=3.9)

https://doi.org/10.1002/chem.202303580

6. X.-T. Bai, L.-H. Cao*, C. Ji, F. Zhao, X.-Y. Chen, X.-J. Cao, and M.-F. Huang, Ultra-High Proton Conductivity iHOF Based on Guanidinium Arylphosphonate for Proton Exchange Membrane Fuel Cells, Chem. Mater., 2023, 35, 3172?3180. (IF₂₀₂₃=7.2)

https://doi.org/10.1021/acs.chemmater.2c03817

7. X.-Y. Chen, L.-H. Cao*, X.-T. Bai, X.-J. Cao, D. Yang, and Y.-D. Gao, Superprotonic Conductivity of Guanidinium Organosulfonate Hydrogen-Bonded Organic Frameworks with Nanotube-Shaped Proton Transport Channels, Precis. Chem., 2023, 1, 608?615. (新刊無影響因子)

https://doi.org/10.1021/prechem.3c00094

8. F. Zhao, L.-H. Cao*, and C. Ji, Proton conduction of an ionic HOF with multiple water molecules and application as a membrane filler in direct methanol fuel cells, J. Mater. Chem. C, 2023, 11, 15288-15293. (IF₂₀₂₃=5.7)

https://doi.org/10.1039/D3TC03123C

9. X.-Y. Chen, L.-H. Cao*, M.-F. Huang, Y. Yang, Y.-D. Gao, X.-T. Bai, and D. Yang, Water-Induced Single-Crystal to Single-Crystal Transformation of Ionic Hydrogen-Bonded Organic Frameworks with Enhanced Proton Conductivity, Chem. Eur. J., 2023, 29, e202300028. (IF₂₀₂₃=3.9)

https://doi.org/10.1002/chem.202300028

10. X.-T. Bai, L.-H. Cao*, X.-Y. Chen, X.-J. Cao, W.-C. Meng, and K.-Y. Yan, A Sodium-Based Phosphonates Metal?Organic Framework with Superprotonic Conductivity, Cryst. Growth Des., 2023, 23, 8488?8493. (IF₂₀₂₃=3.2)

https://doi.org/10.1021/acs.cgd.3c01102

11. F. Zhao, L.-H. Cao*, X.-T. Bai, X.-Y. Chen, and Z. Yin, Application of Ionic Hydrogen-Bonded Organic Framework Materials in Hybrid Proton Exchange Membranes, Cryst. Growth Des., 2023, 23, 1798?1804. (IF₂₀₂₃=3.2)

https://doi.org/10.1021/acs.cgd.2c01306

12. Y. Yang, X.-Y. Chen, X.-M. Li, F. Zhao, X.-T. Bai and L.-H. Cao*, Enhanced proton conduction of crystalline organic salt hybrid membranes and the performance of fuel cells, Mater. Chem. Front., 2022, 6, 3402–3408. (IF₂₀₂₂=7.0)

https://doi.org/10.1039/D2QM00656A

13. Y.-W. Tang, X.-Y. Chen, F. Zhao, X.-T. Bai, Z. Yin, and L.-H. Cao*, Enhanced Proton Conductivity of an Ionic Hydrogen-Bonded Organic Framework-Embedded Nafion Matrix, Energy Fuels, 2022, 36, 12772?12779. (IF₂₀₂₂=5.3)

https://doi.org/10.1021/acs.energyfuels.2c02520

14. L.-H. Cao*, Y. Yang, X.-H. Tang, X. Wang, and Z. Yin, Substituent Controlled Framework Transformation Based on Solvent-Assisted Linker Exchange, Cryst. Growth Des. 2022, 22, 37-42. (IF₂₀₂₂=3.8) https://doi.org/10.1021/acs.cgd.1c00949

15. X.-Q. Xu, L.-H. Cao*, Y. Yang, F. Zhao, X.-T. Bai, and S.-Q. Zang, Hybrid Nafion Membranes of Ionic Hydrogen-Bonded Organic Framework Materials for Proton Conduction and PEMFC Applications, ACS Appl. Mater. Interfaces 2021, 13, 56566?56574. (IF₂₀₂₁=10.383) https://doi.org/10.1021/acsami.1c15748

16. L.-H. Cao*, X.-Q. Xu, X.-H. Tang, Y. Yang, J. Liu, Z. Yin, S.-Q. Zang, and Y.-M. Ma, Controllable Strategy for Metal?Organic Framework Light-Driven [2 + 2] Cycloaddition Reactions via Solvent-Assisted Linker Exchange, Inorg. Chem. 2021, 60, 2117?2121. (Supplementary Cover, IF₂₀₂₁=5.436)

https://dx.doi.org/10.1021/acs.inorgchem.0c02999

17. X.-Q. Xu, L.-H. Cao*, Y. Yang, X.-T. Bai, F. Zhao, Z.-H. He, Z. Yin, and Y.-M. Ma, Cationic Nonporous Macrocyclic Organic Compounds for Multimedia Iodine Capture, Chem Asian J. 2021, 16, 142?146. (IF₂₀₂₁=4.839)

https://doi.org/10.1002/asia.202001298

（核稿：黃文歡 編輯：王亮）