@article{Li2026, 
author = {Liqing Li and Xinming Wang and Jian Li and Yufang Wang and Haijun Pang and Huiyuan Ma},
title = {Rational design of hexanuclear zirconium-cluster-based porphyrinic metal-organic frameworks for high-efficiency electrocatalytic nitrate reduction to ammonia},
year = {2026},
journal = {Polyoxometalates},
volume = {5},
number = {2},
pages = {9140116},
keywords = {porphyrinic metal-organic frameworks, green ammonia synthesis, copper electrocatalyst, electrocatalytic nitrate reduction},
url = {https://www.sciopen.com/article/10.26599/POM.2026.9140116},
doi = {10.26599/POM.2026.9140116},
abstract = {Green ammonia (NH3) synthesis is pivotal for sustainable agriculture and hydrogen energy carriers; however, challenges persist in direct electrocatalytic nitrate reduction (e-NO3RR) under neutral conditions, including competing hydrogen evolution and sluggish reaction kinetics. Herein, a series of transition-metal–porphyrin metal-organic frameworks (MOFs), NU-902(M) (M = Fe, Co, Ni, Cu), are engineered via coordination between metalated tetrakis(4-carboxyphenyl)porphyrin (M-TCPP) and Zr6O4(OH)4(CO2)12 clusters, constructing a hierarchical mesoporous architecture. Notably, NU-902(Cu) achieves a Faradaic efficiency (FE) of 71.65% with an NH3 yield rate of 13.76 mg·h−1·mgcat.−1 at −0.9 V vs. reversible hydrogen electrode (RHE), outperforming analogous frameworks based on Fe (14.01 mg·h−1·mgcat.−1, 63.83%), Co (9.51 mg·h−1·mgcat.−1, 71.51%), and Ni (2.40 mg·h−1·mgcat.−1, 67.99%). Moreover, the FE of NU-902(Cu) remains above 65% after 500 cycles, and powder X-ray diffraction characterization confirms no significant collapse of the framework structure, indicating excellent structural stability. This work establishes porphyrinic MOFs as efficient platforms for sustainable nitrogen valorization and provides experimental guidance for modulating metal-specific activity in electrocatalysis.}
}