(CH3)2NH-Assisted Synthesis of High-Purity Ni-HKUST-1 for the Adsorption of CO2, CH4, and N2

Graphical Both high selectivity and adsorption capacity in the adsorptive separation of CO 2 , CH 4 , and N 2 were achieved by means of (CH 3 ) 2 NH functionalization of the unsaturated metal sites of the MOF Ni-HKUST-1. Ni-HKUST-1, with the same topological structure as Cu-BTC (HKUST-1), was synthesized by a (CH 3 ) 2 NH-assisted method. Ni-HKUST-1 with high purity (> 90 %), yield (85 %), and BET surface area (1088 m 2 /g) was successfully synthesized for the first time by using NiCl 2 . The pure-component adsorption isotherms of CO 2 , CH 4 , and N 2 on Ni-HKUST-1 were measured by the volumetric method and the data used to estimate the separation selectivity for CO 2 /CH 4 , CH 4 /N 2 , and CO 2 /N 2 binary mixtures according to the ideal adsorbed solutions theory. At 273 K and 1 atm, the selectivities for CO 2 /CH 4 , CH 4 /N 2 , and CO 2 /N 2 were 14.49, 5.36, and 183.41, respectively, and the adsorption capacities for CO 2 and CH 4 were 223.87 and 67.89 cm 3 /g, respectively. This is a rare demonstration of both high selectivity and adsorption capacity in the separation of CO 2 , CH 4 , and N 2 .