Gas Uptake and Supercapacitor Performance of a Highly Connected Porous Co-Metal–Organic Framework Induced by Ligand Bulk

Abstract

The mimic of a (3,9)-connected xmz framework generates a novel highly connected Co-metal–organic framework (SNNU-80) constructed by trigonal prismatic [Co3(OH)(COO)6] building blocks and tripodal pyridyl-dicarboxylate ligands (BPYDB = 4,4′-(4,4′-bipyridine-2,6-diyl)-dibenzoic acid). Compared to the nonporous Co-pyridine-3,5-dicarboxylate xmz metal–organic framework (MOF), the extension of a triangular linker leads to a different geometrical distribution of ligands and thus a porous structure with the topology of 3,3,9T2 for SNNU-80. Four types of polyhedral cages coexist together, which produce permanent micro- and mesoporosity. Different from MCF-18 assembled by BPYDB with [Ni3(OH)(COO)6] showing drastic framework breathing, SNNU-80 is not flexible. As a result, SNNU-80 shows remarkable CO2 uptake capacity as well as high CO2 and C2 hydrocarbons over CH4 selectivity. Furthermore, the electrochemical measurements show that SNNU-80 is an idea electrode material for supercapacitors due to its highly connected stable porous framework and the pseudocapacitor contribution introduced by the mixed valent system.