Remarkable adsorbent for phenol removal from fuel: Functionalized metal-organic framework

Adsorption of phenol from a model fuel was firstly conducted over activated carbon (AC) and a typical porous metal-organic framework (MOF, MIL-101) in order to understand the possible application of MOFs in fuel purification. MIL-101 showed a remarkable phenol adsorption capacity (similar to 2.7 times that of AC) under the studied conditions. Moreover, the adsorption capacity enhanced further (up to similar to 3.7 times of AC) after introduction of a hydroxyl group on the MOF (even though porosity of the MOF was decreased noticeably) by grafting ethanolamine (EA) on coordinatively unsaturated sites on MIL-101. The adsorption of phenol on EA-grafted MIL-101 (HO-MIL-101) is explained by H-bonding. Comparative adsorption of phenol and anisole on MIL-101 and HO-MIL-101 suggests that H-bonding occurs between the H-atom of the phenolic -OH and the O-atom of HO-MIL-101. HO-MIL-101 is recyclable after simple solvent washing, showing the potential application of MOFs, if suitably functionalized, for phenol adsorption/removal from fuel. (c) 2016 Elsevier Ltd. All rights reserved.