Silver Nanoparticle-Embedded Zirconium-Based Metal-Organic Framework for Photoreduction of Carbon Dioxide to Acetic Acid in Aqueous Medium

Abstract

Catalytic conversion of CO2 into value-added chemicals is necessary to mitigate the increasing global warming and energy-related issues. The selective production of C2 or C2+ products by photoreduction of CO2 is a challenging task due to the sluggish kinetics of C─C coupling. Herein, the potential of a silver nanoparticle (Ag NP) incorporated metal-organic framework (MOF), NU-1000 is introduced, to harvest light and ease the uphill electron transfer. The growth of silver nanoparticles on thiol-functionalized NU-1000 is studied using the atomic pair distribution function (PDF) analysis. The C2 product formed using Ag@NU-1000-SH without any sacrificial agents is acetic acid, which is confirmed by 1H-NMR and HRMS data. The catalyst displays a high acetate output of 293.58 µmolg−1h−1 with a selectivity of 79.4%. The XPS and DFT calculations evidence that the presence of the charge-polarised states in the as-synthesized catalyst act as asymmetric centers that favor the C─C coupling reaction. The combined experimental (in situ DRIFT spectroscopic studies) and theoretical calculations reveal that the C─C coupling takes place via the coupling of COOH*intermediates. © 2024 Wiley-VCH GmbH.