High Ammonia Uptake of a Metal–Organic Framework Adsorbent in a Wide Pressure Range

Abstract Although numerous porous adsorbents have been investigated for NH 3 capture applications, these materials often exhibit insufficient NH 3 uptake, low NH 3 affinity at the ppm level, and poor chemical stability against wet NH 3 conditions. The NH 3 capture properties of M 2 (dobpdc) complexes (M=Mg 2+ , Mn 2+ , Co 2+ , Ni 2+ , and Zn 2+ ; dobpdc 4− =4,4‐dioxidobiphenyl‐3,3‐dicarboxylate) that contain open metal sites is presented. The NH 3 uptake of Mg 2 (dobpdc) at 298 K was 23.9 mmol g −1 at 1 bar and 8.25 mmol g −1 at 570 ppm, which are record high capacities at both pressures among existing porous adsorbents. The structural stability of Mg 2 (dobpdc) upon exposure to wet NH 3 was superior to that of the other M 2 (dobpdc) and the frameworks tested. Overall, these results demonstrate that Mg 2 (dobpdc) is a recyclable compound that exhibits significant NH 3 affinity and capacity, making it a promising candidate for real‐world NH 3 ‐capture applications.