ImprovingCH4/N2selectivity within isomeric Al-based MOFs for the highly selective capture of coal-mine methane

作者：Lv, Daofei; Wu, Ying; Chen, Jiayu; Tu, Yuanhua; Yuan, Yinuo; Wu, Houxiao; Chen, Yongwei; Liu, Baoyu; Xi, Hongxia^*; Li, Zhong; Xia, Qibin^*

来源：AICHE Journal, 2020, 66(9): e16287.

DOI：10.1002/aic.16287

• CH4
• N(2)separation
• coal-mine methane
• improving selectivity
• isomeric MOFs
• symmetric polar sites

Selectively separating CH(4)from N(2)in coal-mine methane is significantly important in the chemical industry, but challenging and energy-intensive. Using porous materials as adsorbents can separate CH4/N(2)mixtures with low energy consumption, but most adsorbents encounter the problem of poor separation selectivity. Here, we propose a strategy for improving CH4/N(2)selectivity by controlling pore wall environment in two isomeric Al-based metal-organic frameworks (MOFs) with four highly symmetric polar sites for strengthened adsorption affinity toward CH(4)over N-2. At 298 K and 100 kPa, CAU-21-BPDC with four highly symmetric polar sites in the pore walls exhibits 2.4 times higher CH4/N(2)selectivity than CAU-8-BPDC without four highly symmetric polar sites. Gas adsorption isotherms, CH4/N(2)selectivity calculations,Q(st)of CH4, interaction energy calculations, adsorption density distributions of CH(4)and N-2, and breakthrough curves reveal that CAU-21-BPDC is a potential candidate for selective capture coal-mine methane.

• 单位
  广东工业大学