Yes succulent plants do purify the air.
The succulent plants take in air and then release it back into the air as carbon dioxide just like humans breathing in the air and then releasing carbon dioxide.
The succulent plants are good at purifying the air and removes toxins from the air.
Succulents go through the process of photosynthesis during which they release oxygen and during the night the succulent plants respire like humans, releasing carbon dioxide.
Succulents are good plants to have indoors and make an inviting room as well as helping to purify the air.
I breathe much better and so does my family since I have put succulent plants in our home.