Regulating the Pore Microenvironment of Microporous Metal–Organic Frameworks for Efficient Adsorption of Low-Concentration Ammonia

Efficient capture of low-concentration ammonia (NH3) is of great importance for human health and environmental protection. The structural designability and diversity of metal–organic frameworks (MOFs) make these porous adsorbents strong candidates for NH3 uptake. However, developing stable and efficient MOFs for low-concentration ammonia adsorption remains a challenge. Here, super-stable CAU-10-based MOFs have been designed under the guidance of hard and soft acid–base theory to regulate the pore microenvironment of microporous MOFs by simply introducing −OH and μ-OH groups. The as-synthesized CAU-10-OH exhibits excellent adsorption capacity, high selectivity for low-concentration NH3, and low-energy consumption desorption. Notably, CAU-10-OH shows ultralong stability and retains high ammonia capture capacity after 2 years of storage. It is found that such superior performance is mainly ascribed to multiple hydrogen bonding interactions between CAU-10-OH and NH3 molecules (μ-OH···NH3 and −OH···NH3).