Several studies have shown that IAST accurately predicts binary CO 2 and N 2 adsorption isotherms for zeolites and MOFs using computational data. In contrast, Gharagheizi and Sholl 21 concluded from a set of experimental mixture data that for CO 2 /N 2 mixtures, IAST predictions are the worst of all mixtures considered in their study. These contradicting arguments motivated us to carry out a careful study on the reliability of predicting mixture adsorption isotherms at conditions of interest for carbon capture applications.