Constructing Well-Defined and Robust Th-MOF-Supported Single-Site Copper for Production and Storage of Ammonia from Electroreduction of Nitrate

[Image: see text] A combined technique of production and storage of ammonia (NH(3)) from electroreduction of nitrate (NO(3)(–)) through one material is highly desirable but remains a huge challenge. Herein, we proposed a proof-of-concept strategy for combined NH(3) production and storage from electroreduction of NO(3)(–) through elaborately designing a single-site Cu(II)-bipyridine-based thorium metal–organic framework (Cu@Th-BPYDC). Noticeably, the single Cu(II) site, anchored by a solid–liquid postsynthetic metalation within Th-BPYDC, shows a novel square coordination structure, as determined by the single-crystal X-ray diffraction. This strongly implies its enormous potential as an open metal site and consequently enables excellent performance in electroreduction of NO(3)(–) for NH(3) production, giving 92.5% Faradaic efficiency and 225.3 μmol h(–1) cm(–2) yield. Impressively, we can further use Cu@Th-BPYDC material to effectively capture the previously produced NH(3) from electroreduction of NO(3)(–), affording an uptake up to 20.55 mmol g(–1) at 298 K at 1 bar. The results in this work will outline a new direction toward the combined technique for advanced electrocatalysis such as gas production plus storage/or separation.