Catalytic oxygen evolution from hydrogen peroxide by trans-[Co(en)2Cl2]@InBTB metal–organic framework catalytic system

Abstract

The diethylammonium counter-cations of the [Et₂NH₂]₃[In₃(BTB)₄] metal–organic framework (InBTB MOF, BTB = 1,3,5-benzenetribenzoate) with an anionic framework can be effectively exchanged with cationic trans-[Co(en)₂Cl₂]⁺ complex ions through a simple cation-exchange process. The heterogenized trans-[Co(en)₂Cl₂]⁺-encapsulated InBTB MOF (trans-[Co(en)₂Cl₂]@InBTB) catalytic system maintained the activity of the captured trans-[Co(en)₂Cl₂]⁺ complex ion for hydrogen peroxide decomposition in aqueous solution under mild reaction conditions. The captured trans-[Co(en)₂Cl₂]⁺ complex also exhibited trans–cis isomerization to produce either cis-[Co(en)₂Cl₂]@InBTB or cis-[Co(en)₂(H₂O)Cl]@InBTB based on IR spectroscopic investigation. The trans-[Co(en)₂Cl₂]@InBTB catalytic system showed high recyclability for oxygen evolution from hydrogen peroxide. The catalytic ability of trans-[Co(en)₂Cl₂]@InBTB was maintained up to seven times of recycling.