A 9-Connected Zirconium-Based Metal-Organic Framework for Ammonia Capture

Construction of multifunctional metal-organic frameworks (MOFs) with asymmetric connectivity have the potential to expand the scope of their utilization. Herein, we report a robust 9-connected microporous Zr-based MOF, NU-300 , assembled from asymmetric tri-carboxylate ligands and Zr 6 nodes. As indicated by single-crystal X-ray diffraction analysis, there exist uncoordinated carboxylate groups in the structure of NU-300 that can participate in ammonia (NH 3 ) sorption through acid-base interactions which yield high uptake of NH 3 at low pressure regions (<0.01 bar). In situ infrared (IR) spectroscopy shows the interactions between Brønsted acidic sites and NH 3 , which suggests that NU-300 can be used as a sorbent for NH 3 capture at low pressures.