An unprecedented water stable acylamide-functionalized metal-organic framework for highly efficient CH4/CO2 gas storage/separation and acid-base cooperative catalytic activity

The high porosity, excellent water stability and optimized supramolecular host-guest interactions of MOFs are the three key factors for their potential practical applications in many important areas including gas storage/separation, catalysis and so on. In this study, we designed and constructed a highly porous (3, 36)-connected txt-type acylamide-functionalized metal-organic framework (HNUST-8) from a pyridine-based acylamide-linking diisophthalate and dicopper(ii)-paddlewheel clusters. Interestingly, HNUST-8 possesses an exceptionally water-stable framework with a high BET surface area of about 2800 m(2) g(-1). At 298 K, HNUST-8 exhibits a high excess CO2 uptake of 19.7 mmol g(-1) at 40 bar, an excellent total CH4 storage capacity of 223 cm(3)(STP) cm(-3) with a large working capacity of 178 cm(3)(STP) cm(-3) at 80 bar, as well as highly efficient CO2/CH4 and CO2/N-2 separation under dynamic conditions at 1 bar. Moreover, with the Lewis acidic open copper(ii) sites and Lewis basic acylamide groups integrated into the framework, HNUST-8 demonstrates efficient catalytic activity as an acid-base cooperative catalyst in a tandem one-pot deacetalization-Knoevenagel condensation reaction.