Concentration‐Adaptive Electrocatalytic Urea Synthesis From CO2 and Nitrate via Porphyrin and Metalloporphyrin MOFs

• Published in: Angewandte Chemie International Edition Vol. 64; no. 35; pp. e202513441 - n/a
• Main Authors: Tan, Yi, Chen, Xiaokang, Yuan, Jian, Sheng, Guan, Deng, Wei‐Qiao, Wu, Hao
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 25.08.2025
• Edition: International ed. in English
• Subjects: Carbon dioxide; Copper; Coupling; Density functional theory; Electrocatalysts; Emissions; Energy consumption; Greenhouse gases; Hydrogen bonding; Intermediates; Metal-organic frameworks; Nitrate concentration; Nitrates; Nitrogen dioxide; Porphyrin; Porphyrins; Side reactions; Spectroscopy; Synthesis; Urea; Urea synthesis
• ISSN: 1433-7851; 1521-3773; 1521-3773
• DOI: 10.1002/anie.202513441

Traditional urea synthesis via the Bosch–Meiser process suffers from high energy consumption and greenhouse gas emissions. Electrocatalytic urea production from carbon dioxide (CO2) and nitrate (NO3−) under ambient conditions offers a sustainable alternative, yet challenges persist due to variable NO3− concentrations and competing side reactions. Herein, we propose porphyrin metal‐organic framework (PMOF) and Cu‐porphyrin MOF (Cu‐PMOF) catalysts for NO3− concentration‐adaptive urea synthesis. Density functional theory (DFT) calculations reveal that PMOF weakly adsorbs *NO2 via hydrogen bonding, favoring its coupling with *CO2, while Cu‐PMOF strongly binds *NO2 at Cu sites, facilitating spontaneous *NO/*CO coupling to form *OCNO intermediates under dilute NO3− conditions. Experimentally, PMOF achieves a urea yield of 28.6 µmol h−1 mgcat−1 and a Faradaic efficiency (FE) of 23.1% in 0.1 M NO3−, whereas Cu‐PMOF outperforms in 0.05 M NO3− with a yield of 25.5 µmol h−1 mgcat−1 and FE of 52.7%. In situ spectroscopy and mechanistic study confirm distinct pathways: PMOF relies on stepwise coupling of *HNO2 with *CO2, while Cu‐PMOF enables consecutive *NO‐*CO coupling. This work highlights adaptive electrocatalyst design for efficient C‐N coupling, advancing sustainable urea synthesis. This study introduces porphyrinic metal‐organic frameworks (PMOF) and Cu‐metallated PMOF for adaptive electrocatalytic urea synthesis from carbon dioxide (CO2) and nitrate (NO3−), addressing concentration‐dependent challenges. PMOF facilitates *HNO2‐*CO2 coupling under concentrated NO3−, while Cu‐porphyrin MOF (Cu‐PMOF) promotes *NO‐*CO coupling in dilute conditions, with theoretical calculations and in situ studies revealing distinct C‐N coupling pathways for sustainable urea production.