Gallate-Based Metal–Organic Frameworks for Highly Efficient Removal of Trace Propyne from Propylene
Zhu Li, Liangying Li, Lidong Guo, Jiawei Wang, Qiwei Yang, Zhiguo Zhang, Yiwen Yang, Zongbi Bao, Qilong Ren
Abstract
Purification of propylene from the propyne (C3H4)/propylene (C3H6) mixture is a significant and challenging process in the chemical industry. Nowadays, the removal of propyne from propylene mainly relies on the energy-intensive hydrogenation catalyzed by noble metals. We herein report three gallate-based metal–organic frameworks, namely, M(II)-gallate (M = Ni, Mg, Co), which provide excellent performance in terms of removing propyne from the propyne/propylene mixture (1:99, v/v). The C3H4 uptake capacities of Mg-, Co-, and Ni-gallate can reach 3.75, 3.21, and 2.65 mmol/g, while the C3H6 uptake capacities are only 1.50, 1.49, and 0.9 mmol/g respectively, at ambient conditions. Particularly, the productivities of 99.9999% pure C3H6 in Co-gallate and Mg-gallate were 1580 and 1420 mL/g, respectively, outperforming the state-of-the-art material USTA-200 (1400 mL/g). The adsorption mechanism was further investigated by using the first-principle dispersion-corrected density functional theory calculations, revealing that the excellent C3H4/C3H6 separation ability of M-gallate originates from stronger supramolecular interactions and C–H···O interactions between the hydrogen atoms from C3H4 and oxygen atoms from M-gallate frameworks. Besides, the M-gallate materials also show excellent regeneration ability. Thus, this work demonstrates that the family of M-gallate materials shows industrially promising porous materials for propylene purification by the adsorption process.