From Arm and Hammer:
Baking soda
So if I put an open box of it in my fridge, it works by deprotonating adsorbed acidic odorants? Would any weak base work? Are all (most?) important household odorants acidic? Is there really enough air exchange between the refrigerator compartment and a little box for it to be effective in this regard?
I always thought that baking soda simply adsorbed the molecules responsible for smells. Its finely ground, so lots of surface area is available. Activated carbon would be better, but more expensive.
Baking soda is good because it can neutralize both acids and bases. It is known as a buffer. It can very readily absorb or donate protons while not changing its pH very much. Any chemical that buffers to near neutral pH would work in a similar fashion.
That said, I don’t discount the role that the baking soda being in powder form plays. I am sure it certainly helps get the oder molecules near the baking soda molecules.