Improving the Porosity and Catalytic Capacity of a Zinc Paddlewheel Metal-Organic Framework (MOF) through Metal-Ion Metathesis in a Single-Crystal-to-Single-Crystal Fashion

Zinc
paddlewheel metal-organic frameworks (MOFs) frequently exhibit low
stability or complete collapse upon the removal of axial ligands.
Hence, there are very few reports on gas adsorption of zinc paddlewheel
MOFs. In this work, the N2 and H2 adsorption
measurements were carried out for a zinc MOF (namely, SDU-1) based on two types of paddlewheel secondary building units (SBUs):
[Zn2(COO)3] and [Zn2(COO)4]. Because of the existence of inherent
surface instability upon removal of solvates in zinc paddlewheel SBU, SDU-1 possesses a very low surface area. Through metal-ion
metathesis in a single-crystal-to-single-crystal fashion, the Zn2+ ions in SDU-1 were exchanged by Cu2+ ions to generate Cu-SDU-1. Through the measurements
of gas adsorption and catalytic test, the porosity and catalytic capacity
of Cu-SDU-1 have been improved significantly, compared
to SDU-1.