Cu(I) doping of octahedral MIL-100(Fe) was successfully performed by means of impregnation and consequent reduction under vacuum conditions. Although MIL-100(Fe) adsorbed CO2 better than CO, Cu(I)@MIL-100(Fe) showed selective CO adsorption compared to CO2 owing to π complexation between CO and Cu(I). Effects of Cu(I) loading concentration, activation temperature, and adsorption temperature upon CO/CO2 adsorption properties were systematically investigated. The adsorption behaviors of CO and CO2 on MIL-100(Fe) and Cu(I)@MIL-100(Fe) were well described by the dual-site Langmuir–Freundlich (DSLF) model. Ideal adsorbed solution theory (IAST) was used to predict adsorption isotherms of equimolar CO and CO2 mixtures and to predict CO/CO2 selectivities as a function of bulk pressure. The obtained results showed that 45 wt% Cu(I)-doped MIL-100(Fe) had CO adsorption capacity of 3.10 mmol g−1 and CO/CO2 selectivity of 420 at 298 K and 1 bar. In addition, a large CO working capacity of 1.39 mmol g−1 was observed for 45 wt% Cu(I)-doped MIL-100(Fe) in the pressure range of 10–100 kPa. Cu(I)-doped MIL-100(Fe) thus appears promising as an adsorbent material for effective CO/CO2 separation.
Bibliographical noteFunding Information:
This work was supported by “ Next Generation Carbon Upcycling Project ” ( NRF-2017M1A2A2043451 ) and the Engineering Research Center of Excellence Program ( NRF-2014R1A5A1009799 ) through the National Research Foundation funded by the Ministry of Science and ICT, Republic of Korea.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials