In situ casting of rice husk ash in metal organic frameworks induces enhanced CO(2) capture performance

Incorporation of rice-husk-ash (RHA), an agricultural waste, in situ during the synthesis of MIL-101(Cr) resulted in a significant improvement in the CO(2) adsorption properties over the synthesized RHA-MIL-101(Cr). The newly synthesized RHA-MIL-101(Cr) composite exhibited an enhancement of 14–27% in CO(2) adsorption capacity as compared to MIL-101(Cr) at 25 °C and 1 bar. The content of RHA incorporated in RHA-MIL-101(Cr) fine tuned the CO(2) capture performance to achieve high working capacity (0.54 mmol g(−1)), high purity (78%), superior CO(2)/N(2) selectivity (18) and low isosteric heat of adsorption (20–30 kJ mol(−1)). The observed superior CO(2) adsorption performance of RHA-MIL-101(Cr) is attributed to the fine tuning of textural characteristics—enhancement of 12–27% in BET surface area, 12–33% in total pore volume and 18–30% in micropore volume—upon incorporation of RHA in MIL-101(Cr).