Construction of thermally and chemically robust metal-organic frameworks (MOFs) is highly desirable for postcombustion CO2 capture from flue gas containing water vapor and other acidic gases. Here we report a strategy based on appending amino groups to the triazolate linkers of MOFs to achieve exceptional chemical stability against aqueous, acidic, and basic conditions. These MOFs exhibit not only CO2/N-2 thermodynamic adsorption selectivity as high as 120 but also CO2/H2O kinetic adsorption selectivity up to 70, featuring distinct adsorptive sites at the channel center for CO2 and at the corner for H2O, respectively. The best performing MOF in this series features low regeneration energy, high CO2 capture utility under humid conditions, and decent cycling performance for mimic flue gas.