Integration of accessible secondary metal sites into MOFs for H2S removal

Abstract

2,2′-Bipyridine-5,5′-dicarboxylic acid (H₂bipy) was used for the synthesis of a zirconium based metal–organic framework with the aim to integrate an additional N-donor coordination functionality into the framework. The resulting MOF (UiO-67(bipy)) with a structure isoreticular to UiO-67 (UiO – University of Oslo) has a BET surface area up to 2500 m² g⁻¹. The chelating bipyridine moiety was used for postsynthetic functionalization of the MOF with different metal salts (M^IIX_y; M = Cu²⁺, Ni²⁺, Co²⁺; X = Cl⁻, NO₃⁻, SO₄²⁻, acac²⁻) to give the corresponding metal_salt@UiO-67(bipy) materials. Due to the highly dispersed metal ions, metal_salt@UiO-67(bipy) shows good performance in toxic hydrogen sulfide capture. Especially, the copper loaded samples have high capacities of up to 7.8 wt%.