Thermal Shrinkage Behavior of Metal–Organic Frameworks

Thermal treatment of metal–organic frameworks (MOFs) as a post-treatment approach has grown in popularity and resulted in various MOF-derived materials. However, the widely used extreme thermolytic conditions (usually above 500 °C) lead to degradation in the well-defined MOFs intrinsic properties. This work demonstrates that MIL-101 calcined at medium-temperature range (200–280 °C) partially breaks the coordination bonds that can introduce more accessible active sites, exhibiting a 10-fold increase in oxidation activity while retaining its intrinsic structure and porosity. Another fascinating feature of MIL-101 calcined in this temperature range is their temperature-dependent shrinkage behavior, which is also found in many other types of MOFs. Based on different shrinkage ratios of various MOFs, yolk–shell MOFs@MOFs structures can be constructed through nonsacrificial template method. Overall, the structural and morphological evolution process of MOFs treated in the medium-temperature range can open new horizons to develop efficient MOFs catalysts and design complex structures.