Efficient capture and storage of ammonia in robust aluminium-based metal-organic frameworks
Lixia Guo, Joseph Hurd, Meng He, Wanpeng Lu, Jiangnan Li, Danielle Crawshaw, Mengtian Fan, Sergei Sapchenko, Yinlin Chen, Xiangdi Zeng, Meredydd Kippax‐Jones, Wenyuan Huang, Zhaodong Zhu, Pascal Manuel, Mark D. Frogley, Daniel Lee, Martin Schröder, Sihai Yang⧫
Abstract
Abstract The development of stable sorbent materials to deliver reversible adsorption of ammonia (NH 3 ) is a challenging task. Here, we report the efficient capture and storage of NH 3 in a series of robust microporous aluminium-based metal-organic framework materials, namely MIL-160, CAU-10-H, Al-fum, and MIL-53(Al). In particular, MIL-160 shows high uptakes of NH 3 of 4.8 and 12.8 mmol g −1 at both low and high pressure (0.001 and 1.0 bar, respectively) at 298 K. The combination of in situ neutron powder diffraction, synchrotron infrared micro-spectroscopy and solid-state nuclear magnetic resonance spectroscopy reveals the preferred adsorption domains of NH 3 molecules in MIL-160, with H/D site-exchange between the host and guest and an unusual distortion of the local structure of [AlO 6 ] moieties being observed. Dynamic breakthrough experiments confirm the excellent ability of MIL-160 to capture of NH 3 with a dynamic uptake of 4.2 mmol g −1 at 1000 ppm. The combination of high porosity, pore aperture size and multiple binding sites promotes the significant binding affinity and capacity for NH 3 , which makes it a promising candidate for practical applications.