Catalytic converter dimensions (do not need to build, just theory)?

I'm currently a chemical engineer at UCLA. For a project, I'm supposed to find a way for average households to decrease the amount of CO2 emission into the environment. I'm targeting the chimney as where the designed system will be. Right now, the idea is like a catalytic converter, except instead of catalysts, there will be adsorbants within to adsorb the CO2 gas leaving the house. However, I have no clue on how to design the dimensions of a catalytic converter. What is there to consider when designing the diameter of the entrance and the exit? The size of the entire converter, the diameter of the core/gap between core and hardcase/ thickness of hardcase? etc. All the references found had no specific equations (if there is any) but only the reason of why there is a large gap, etc or no figures to indicate what it's referring to. Also, since I'm replacing the catalyst with adsorbant, many of these reasons don't apply, so I was wondering if there's any general rules to consider? THANKS