Cu-TDPAT, an rht-Type Dual-Functional Metal–Organic Framework Offering Significant Potential for Use in H₂ and Natural Gas Purification Processes Operating at High Pressures

The separations of CO 2 /CO/CH 4 /H 2, CO 2 /H 2, CH 4 /H 2, and CO 2 /CH 4 mixtures at pressures ranging to 7 MPa are important in a variety of contexts, including H 2 production, natural gas purification, and fuel-gas processing. The primary objective of this study is to demonstrate the selective adsorption potential of an rht -type metal–organic framework [Cu 3 (TDPAT)(H 2 O) 3 ]·10H 2 O·5DMA (Cu-TDPAT), possessing a high density of both open metal sites and Lewis basic sites. Experimental high pressure pure component isotherm data for CO 2, CO, CH 4, and H 2 are combined with the Ideal Adsorbed Solution Theory (IAST) for estimation of mixture adsorption equilibrium. The separation performance of Cu-TDPAT is compared with four other microporous materials, specifically chosen in order to span a wide range of physicochemical characteristics: MgMOF-74, MIL-101, LTA-5A, and NaX. For all mixtures investigated, the capacity of Cu-TDPAT to produce the desired product, H 2 or CH 4, satisfying stringent purity requirements, in a fixed bed operating at pressures exceeding about 4 MPa, is either comparable to, or exceeds, that of other materials.