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Updated: Mar 18, 2026
Author Spotlight: Functionalizing Metal-Organic Frameworks: Advancements, Challenges, and the Power of Post-Synthetic Ligand Exchange
Published on: June 23, 2023
Polymorphism-driven coordination geometry engineering for boosting nitrate electroreduction in Cu-pyrazolate chains
Zhanning Liu1, Shanna An1, Qingzhong Xue1
1School of Materials Science and Engineering, Shandong Key Laboratory of Special Epoxy Resin, Shandong University of Science and Technology Qingdao 266590 China znliu@sdust.edu.cn xueqz@upc.edu.cn jiantian@sdust.edu.cn.
Abstract:
Tailoring the coordination geometry of metal centers through polymorphism offers a powerful approach to isolating the structural origin of catalytic activity in metal-organic frameworks (MOFs). Herein, two copper-pyrazolate (Pz) polymorphs, α-Cu(Pz)2 and β-Cu(Pz)2 were synthesized, featuring identical chemical compositions and 1-periodic chain structures but distinct local coordination configurations. Remarkably, the β-Cu(Pz)2 exhibits a faradaic efficiency (FE) of 93.33% for the nitrate reduction reaction (NO3RR), significantly outperforming α-Cu(Pz)2 (53.10%). Comprehensive structural analyses, in situ spectroscopy, and density functional theory (DFT) calculations revealed that the coordination geometry governs the electronic structure of the Cu active centers. Specifically, the cis-configured β-Cu(Pz)2 enables more delocalized Cu 3d orbitals and stronger Cu-O (NO3 -) electronic coupling, thereby promoting nitrate adsorption and activation. This work demonstrates that MOF polymorphism allows precise tuning of electronic structures, offering a fundamental design principle for the development of advanced electrocatalysts toward sustainable nitrogen-cycle chemistry.
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