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

• Published in: Applied catalysis. B, Environmental Environmental, 2023-06, Vol.327, p.122418, Article 122418
• Main Authors: He, Xiaoyu, Gao, Xutao, Chen, Xiao, Hu, Shen, Tan, Fangchang, Xiong, Yujie, Long, Ran, Liu, Min, Tse, Edmund C.M., Wei, Fei, Yang, Hong, Hou, Jungang, Song, Chunshan, Guo, Xinwen
• Format: Article
• Language: English
• Subjects: Atomically dispersed Fe sites; Carbon dioxide reduction; High selectivity; Metal-organic frameworks; Visible-light driven photocatalysis
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2023.122418

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 photocatalysis 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. [Display omitted] •A MOF-based photocatalyst with atomically dispersed Fe active sites was prepared.•The catalyst delivered a high activity and selectivity toward CO2 photoreduction.•Synergistic coordination of clusters, ligands and Fe sites promotes charge transfer.•The strong O/Fe affinity plays a decisive role on the selectivity to form HCOOH.