Adsorbent based gas storage and separation is an emerging area of research owing to their high crystallinity, surface area, stability and efficient regeneration. Metal-organic frameworks are one of the widely investigated class of material in the past couple of decades as it satisfies the requirements for practical gas storage and separation applications. Zeolitic imidazolate frameworks (ZIFs) are a sub-class of MOFs possessing zeolite like structures, are exceptionally stable in comparison to MOFs making them interesting for practical applications. A few ZIFs, ZIF-8, ZIF-90, ZIF-7, ZIF-11 and ZIF-71, with SOD and RHO topology consisting different functional groups embedded in the framework are chosen for this thesis. The aim of this work will be to investigate effects of topology & functional groups in adsorption of industrially relevant gases like H2¬, CO2, N2 and CH4, which will enable us to improve ZIFs properties depending on the desired application. Pure component adsorption will be investigated using equilibrium gas sorption studies, which will be extended to dynamic breakthrough experiments using binary (or multicomponent) mixtures. Since computational tools are considered to be exceptionally useful for both fundamental understanding and predicting material’s performance, we will also aim to integrate density functional theory (DFT) calculations with our experimental results. As a whole the approach would be to provide a comparative and combined experimental-computational understanding of gas adsorption behaviour in the ZIFs mentioned above.