Subverting the Dominant Paradigm in Metal–Organic Framework Activation

Abstract The necessity of solvent exchange and evacuation for metal–organic framework (MOF) activation is investigated using HKUST-1, UiO-66, and Zn-MOF-74 as model systems. High surface areas are achieved by simple thermal treatment directly from either the synthesis solvent or the activation solvent. The process requires careful control over time and temperature, as removal of guest solvent molecules competes with linker decomposition. Detailed studies on HKUST-1 reveal the liberation of benzene accompanying material decomposition. NMR spectroscopy data complement TGA-MS data to reveal stepwise linker decarboxylation and an autocatalytic decomposition mechanism. Material collapse, evidenced by a surface area decline upon extended thermal treatment, is found to be accelerated by certain residual solvents, albeit with a mechanism distinct from the commonly invoked mechanism of capillary force-induced collapse.