The preparation of MIL-101 was simplified to avoid the use of hazardous hydrofluoric acid (HF). The potential application of MIL-101, prepared by both this new method and the conventional approach, for CO2 isolation from multicomponent mixtures such as flue gas is evaluated with regard to its relative adsorption capacity for different flue gas components and retention of the CO2 capacity in the presence of H2O, because flue gas contains gases other than CO2 and moisture. CO2, CH4, and N-2 isotherms were determined for temperatures in the range 25-105 degrees C and pressures up to 15 bar. CO2 adsorption capacities of 15.4 and 16.8 mol/kg at 25 degrees C and IS bar were determined for conventional (1) and HF-free-synthesized MIL-101 (2), respectively. The shape of the CO2 adsorption isotherm of 1 is slightly different from that of 2. Material 1 showed higher CO2 adsorption at low CO2 pressure at 25 degrees C than 2 but lower CO2 adsorption at CO2 pressures above 8 bar and almost identical adsorption for H2O. Both materials adsorb more CH4 than Ni, and the heat of CO2 adsorption is low. The selectivity of material 2 for CO2 relative to N-2 is higher than that of 1, but for CO2 relative to CH4, it is similar to that of 1. The structures of the two materials remain intact after exposure to H2O vapor at 100 degrees C and 50 mbar H2O vapor pressure.