Coordinating Mesopore Geometry and Interfacial Water Dynamics for Iron‐Site Evolution in Nitrate Electroreduction
9 affiliations
- 1Department of Materials Process Engineering, Graduate School of Engineering Nagoya University Nagoya Japan
- 2Molecular Science and Technology Program Taiwan International Graduate Program Academia Sinica Taipei Taiwan
- 3International Graduate Program of Molecular Science and Technology (NTU‐MST) National Taiwan University Taipei Taiwan
- 4Department of Chemical Engineering National Taiwan University Taipei Taiwan
- 5Center of Atomic Initiative for New Materials (AI‐MAT) National Taiwan University Taipei Taiwan
- 6Department of Chemistry Graduate School of Science Nagoya University Nagoya Japan
- 7Institute of Transformative Bio‐Molecules (WPI‐ITbM) Nagoya University Nagoya Japan
- 8Australian Institute for Bioengineering and Nanotechnology (AIBN) The University of Queensland Brisbane Queensland Australia
- 9Department of Convergent Biotechnology and Advanced Materials Science Kyung Hee University Yongin‐si Gyeonggi‐do South Korea
Abstract
Developing electrocatalysts with active sites that undergo structural evolution under operating conditions remains a challenge in electrochemical nitrate reduction. Here, we use single‐crystalline mesoporous metal–organic frameworks (MOFs) with distinct pore geometries to investigate the potential‐dependent evolution of iron active sites during electrochemical nitrate‐to‐ammonia conversion. Fe single atoms are anchored within hexagonal and cubic mesoporous frameworks, providing two structurally distinct environments for examining their catalytic and working‐state responses. Operando FTIR, H/D isotope‐exchange, and DRT analyses reveal that the 1D hexagonal mesoporous environment is associated with a distinct interfacial‐water response and proton‐involved reaction behavior. This response coincides with changes in the average Fe coordination environment. Operando XAS further reveals potential‐dependent changes in both catalysts, with FeSAs@mUiO‐P exhibiting a more pronounced Fe‐associated higher‐shell contribution and greater post‐potential recovery. Under the investigated conditions, FeSAs@mUiO‐P achieves a Faradaic efficiency of 99.1% at −1.05 V versus RHE and exhibits higher NH3 selectivity than its cubic counterpart. Collectively, these findings reveal a potential‐dependent correspondence among mesopore architecture, interfacial water organization, and Fe‐site evolution. Although the causal relationship between water organization and Fe‐site evolution remains to be established, this correspondence provides a working framework for investigating reaction‐state‐dependent catalytic interfaces.
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BibTeX
@article{liu2026coordinating,
title = {{Coordinating Mesopore Geometry and Interfacial Water Dynamics for Iron‐Site Evolution in Nitrate Electroreduction}},
author = {Xiangyang Liu and Yingji Zhao and Norman C.‐R. Chen and Kevin C.‐W. Wu and Ho Ngoc Nam and Quan Manh Phung and Asep Sugih Nugraha and Yusuke Asakura and Yusuke Yamauchi},
journal = {Angewandte Chemie (International Ed. in English)},
year = {2026},
month = sep,
doi = {10.1002/anie.5865467},
url = {https://doi.org/10.1002/anie.5865467},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Coordinating Mesopore Geometry and Interfacial Water Dynamics for Iron‐Site Evolution in Nitrate Electroreduction
AU - Xiangyang Liu
AU - Yingji Zhao
AU - Norman C.‐R. Chen
AU - Kevin C.‐W. Wu
AU - Ho Ngoc Nam
AU - Quan Manh Phung
AU - Asep Sugih Nugraha
AU - Yusuke Asakura
AU - Yusuke Yamauchi
PY - 2026
DA - 2026/09/19
JO - Angewandte Chemie (International Ed. in English)
DO - 10.1002/anie.5865467
UR - https://doi.org/10.1002/anie.5865467
AB - Developing electrocatalysts with active sites that undergo structural evolution under operating conditions remains a challenge in electrochemical nitrate reduction. Here, we use single‐crystalline mesoporous metal–organic frameworks (MOFs) with distinct pore geometries to investigate the potential‐dependent evolution of iron active sites during electrochemical nitrate‐to‐ammonia conversion. Fe single atoms are anchored within hexagonal and cubic mesoporous frameworks, providing two structurally distinct environments for examining their catalytic and working‐state responses. Operando FTIR, H/D isotope‐exchange, and DRT analyses reveal that the 1D hexagonal mesoporous environment is associated with a distinct interfacial‐water response and proton‐involved reaction behavior. This response coincides with changes in the average Fe coordination environment. Operando XAS further reveals potential‐dependent changes in both catalysts, with FeSAs@mUiO‐P exhibiting a more pronounced Fe‐associated higher‐shell contribution and greater post‐potential recovery. Under the investigated conditions, FeSAs@mUiO‐P achieves a Faradaic efficiency of 99.1% at −1.05 V versus RHE and exhibits higher NH3 selectivity than its cubic counterpart. Collectively, these findings reveal a potential‐dependent correspondence among mesopore architecture, interfacial water organization, and Fe‐site evolution. Although the causal relationship between water organization and Fe‐site evolution remains to be established, this correspondence provides a working framework for investigating reaction‐state‐dependent catalytic interfaces.
SN - 1433-7851
SN - 1521-3773
ER -