Pendant Proton-Relays Systematically Tune the Rate and Selectivity of Electrocatalytic Ammonia Generation in a Fe-Porphyrin Based Metal-Organic Framework

Arnab Ghatak; Shiva Shanker Golla; Subrahmanyam Sappati; Liberman Itamar; Ran Shimoni; Idan Hod

doi:10.1002/anie.202407667

Pendant Proton-Relays Systematically Tune the Rate and Selectivity of Electrocatalytic Ammonia Generation in a Fe-Porphyrin Based Metal-Organic Framework

Abstract

Electrocatalytic nitrite reduction (eNO2RR) is a promising alternative route to produce ammonia (NH3). Until now, several molecular catalysts have shown capability to homogeneously reduce nitrite to NH3, while taking advantage of added secondary-sphere functionalities to direct catalytic performance. Yet, realizing such control over heterogeneous electrocatalytic surfaces remains a challenge. Herein, we demonstrate that heterogenization of a Fe-porphyrin molecular catalyst within a 2D Metal-Organic Framework (MOF), allows efficient eNO2RR to NH3. On top of that, installation of pendant proton relaying moieties proximal to the catalytic site, resulted in significant improvement in catalytic activity and selectivity. Notably, systematic manipulation of NH3 faradaic efficiency (up to 90%) and partial current (5-fold increase) was achieved by varying the proton relay-to-catalyst molar ratio. Electrochemical and spectroscopic analysis show that the proton relays simultaneously aid in generating and stabilizing of reactive Fe-bound NO intermediate. Thus, this concept offers new molecular tools to tune heterogeneous electrocatalytic systems.

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Authors (6)

Arnab Ghatak Ph D
Shiva Shanker Golla Ph. D
Subrahmanyam Sappati dr
Liberman Itamar
Ran Shimoni
Idan Hod

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Keywords

METAL-ORGANIC FRAMEWORK (MOF) FE-PORPHYRIN SECOND SPHERE PROTON RELAY

Details

Category:

Articles

Type:

artykuły w czasopismach

Published in:

ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
ISSN: 1433-7851

Language:

English

Publication year:

2024

Bibliographic description:

Ghatak A., Golla S. S., Sappati S., Itamar L., Shimoni R., Hod I.: Pendant Proton-Relays Systematically Tune the Rate and Selectivity of Electrocatalytic Ammonia Generation in a Fe-Porphyrin Based Metal-Organic Framework// ANGEWANDTE CHEMIE-INTERNATIONAL EDITION -,iss. 1433-7851 (2024),

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