Post Synthetic Defect Engineering of UiO-66 Metal–Organic Framework with An Iridium(III)-HEDTA Complex and Application in Water Oxidation Catalysis

Inorganics

Giordano Gatto¹  Ferdinando Costantino¹  Roberto Bondi¹  Fabio Marmottini¹  Alceo Macchioni¹ 

[1] Department of Chemistry, Biology and Biotechnology, Università di Perugia and CIRCC, Via Elce di Sotto, 8, I-06123 Perugia, Italy;

关键词: metal–organic framework;    post-synthetic modification;    iridium catalysis;    water oxidation;    water splitting;   

DOI  :  10.3390/inorganics7100123

来源: DOAJ

【 摘 要 】

Clean production of renewable fuels is a great challenge of our scientific community. Iridium complexes have demonstrated a superior catalytic activity in the water oxidation (WO) reaction, which is a crucial step in water splitting process. Herein, we have used a defective zirconium metal−organic framework (MOF) with UiO-66 structure as support of a highly active Ir complex based on EDTA with the formula [Ir(HEDTA)Cl]Na. The defects are induced by the partial substitution of terephthalic acid with smaller formate groups. Anchoring of the complex occurs through a post-synthetic exchange of formate anions, coordinated at the zirconium clusters of the MOF, with the free carboxylate group of the [Ir(HEDTA)Cl]⁻ complex. The modified material was tested as a heterogeneous catalyst for the WO reaction by using cerium ammonium nitrate (CAN) as the sacrificial agent. Although turnover frequency (TOF) and turnover number (TON) values are comparable to those of other iridium heterogenized catalysts, the MOF exhibits iridium leaching not limited at the first catalytic run, as usually observed, suggesting a lack of stability of the hybrid system under strong oxidative conditions.

【 授权许可】

Unknown