• Multi-objective BO. We often need to optimize NPMs for multiple property objectives which are conflicting in nature and cannot be optimized simultaneously. For example, for gas separations, we often wish an NPM to have both a high selectivity and a high working capacity for the gas we wish to capture [ ]. For multi-objective optimization problems, we need to find the Pareto optimal set of solutions. A solution Pareto optimal if it cannot be improved in any of the objectives without compromising some other objective. The goal of multi-objective BO is to find the optimal Pareto set of NPMs using fewest NPM evaluations . Similarly, the -PAL algorithm [ ] has recently been used to find the Pareto optimum polymers.