Modulation of NH<sub>2</sub>‐UiO‐66 Based MOFs for Gas Phase CO<sub>2</sub> Photocatalytic Reduction
Marie Duflot, Clément Marchal, Vincent Artero, Konstantinos C. Christoforidis, Valérie Keller
Abstract
Abstract To solve both the greenhouse effect and energy crisis issues, direct capture and conversion of CO 2 appears as a promising contribution. Artificial photosynthesis is an encouraging and very attractive complementary way to convert CO 2 into high‐value‐added chemicals. Nevertheless, efficient CO 2 conversion remains challenging, mainly due to the poor CO 2 adsorption , the high activation energy required to break C═O bonds, and the slow dynamics of charge carriers in light‐harvesting materials. In recent years, some Metal‐organic frameworks (MOFs) have emerged in the photocatalysis field, especially due to their huge CO 2 adsorption capability and light‐harvesting properties behavior. In this study, a series of defective NH 2 ‐UiO‐66 MOF materials, using formic acid (FA) is synthesized as a modulating agent. Then, a series of binary (MOF/TiO 2 ) catalysts is obtained by varying the defective MOFs content, followed by further deposition of gold (Au) nanoparticles (NPs) to result in three‐component MOF/TiO 2 /Au composites. These composites are assessed for gas‐phase CO 2 photoreduction in the presence of water vapor as the only reducing agent. This hybrid ternary photocatalyst not only increases CO 2 adsorption but also promotes CH 4 formation. Among these resulting MOF/TiO 2 /Au samples, the optimized photocatalytic activity results in a mean production rate of 17.2 µmol.h −1 .g −1 catalyst of CH 4 , which is 6‐fold higher than the one observed for the reference TiO 2 /Au photocatalyst.