Understanding Structure–Property Relationships of MOFs for Gas Sensing through Henry’s Constants

In this work, we perform high-throughput computational
screening
of MOFs based on their selectivity of gas mixtures formed by six gas
molecules (H2O, CO2, N2, N2O, CH4, and O2) at dilute conditions using
Henry’s constants. Our results show that pore size is the most
influential geometric factor for high selectivity and therefore should
be highly considered in gas sensor design. Top-performing MOFs were
observed to have high variability for surface area and void fraction
values, and thus, those properties were deemed less important. The
metals present in nodes were found to be important for adsorption
of certain gases and should be taken into account when designing a
sensor for a specific use. A ranking system was applied to find the
best MOFs for sensing multiple gases and then the top 10 MOF’s
properties were examined. We concluded that small pore size and a
smaller difference between largest and smallest pores were ideal for
a highly selective gas sensor. Finally, we recommend some MOF candidates
for selectively adsorbing select gases at dilute conditions.