Dual-optimization strategy engineered Ti-based metal-organic framework with Fe active sites for highly-selective CO2 photoreduction to formic acid

Abstract

<p>Increasing CO₂ conversion efficiency over metal-organic framework (MOF) based photocatalysts is of great significance to promote the carbon capture and utilization. In this work, a dual-benefit design strategy is deployed in the synthesis of a new two-dimensional Fe/Ti-BPDC MOF photocatalyst with atomically dispersed Fe sites. This catalyst demonstrated an excellent catalytic performance in the visible-light-driven CO₂ conversion to HCOOH, achieving a high yield of 703.9 μmol g^-1 h^-1 at a selectivity greater than 99.7%. This is attributed to the ‘dual-optimization’ achieved by this catalyst to sustain the supply of photogenerated electrons and to effectively activate CO₂. Specifically, the Fe/Ti-BPDC catalyst provides a high proportion of effective photogenerated electrons for the CO₂ <a href="https://www.sciencedirect.com/topics/chemical-engineering/photocatalysis" title="Learn more about photocatalysis from ScienceDirect's AI-generated Topic Pages">photocatalysis</a> process via a unique electron transfer mechanism. Meanwhile, the strong O/Fe affinity between CO₂ and atomically dispersed Fe active sites not only enables a fast CO₂ activation, but also dictates the intermediate reaction pathways towards high HCOOH selectivity.<br></p>