Synthesis of porous, nitrogen-doped adsorption/diffusion carbonaceous membranes for efficient CO_2 separation

摘要

A porous, nitrogen-doped carbonaceous free-standing membrane (TFMT-550) is prepared by a facile template-free method using letrozole as an intermediate to a triazole-functionalized-triazine framework, followed by carbonization. Such adsorption/diffusion membranes exhibit good separation performance of CO 2 over N_2 and surpassing the most recent Robeson upper bound. An exceptional ideal CO_2/N_2 permselectivity of 47.5 was achieved with a good CO_2 permeability of 2.40 × 10 ~(~(-1)3) mol m m~(-2) s~(-1) Pa~(-1). The latter results arise from the presence of micropores, narrow distribution of small mesopores and from the strong dipole-quadrupole interactions between the large quadrupole moment of CO_2 molecules and the polar sites associated with N groups (e.g., triazine units) within the framework.