Talk:Benzene/@comment-107.145.172.10-20160229013054/@comment-67.252.74.84-20160524234132

It is possible to catalyze carbon dioxide back into oxygen.

But there's a bigger problem. There's a reason your body breaths in oxygen molecules. Your body needs oxygen to build proteins. So you do not breath out the same amount of oxygen in the form of carbon dioxide as you breathed in oxygen molecules. Some of that oxygen is expelled in your sweat, some of it is expelled in your feces and urine, most of it is expelled as dust (dead skin cells).

In the end, you're using up that oxygen and converting it into an unuseable form. If you're purely relying on your own carbon dioxide exhales to generate new oxygen, you'll eventually suffocate and die from lack of oxygen.