Cracking pollutants is one of our best hopes for removing some kinds of pollutants. For hydrocarbons which are only made of carbon,hydrogen, and some oxygen, you can just burn them. This makes carbondioxide (CO₂) and water, which are both relatively harmless. CO₂ isa greenhouse gas, but it's much less of a danger to the environment than the original hydrocarbons (benzene, unburned gasoline vapors,and so on). You do have to supply extra fuel to keep the fire going,though, which can be expensive. A better way would be to find or genetically engineer a strain of bacteria to attack the particular pollutant you're trying to get rid of. For example, in the town where I grew up, an old railroad yard had dumped a million gallons of diesel fuel into the ground over the years, and the diesel is still contaminating the town's ground water to this day. If you could inject bacteria which "ate" diesel fuel, you could clean up the ground without having to dig it all up. But then one problem is, if you have a bacteria floating around which eats diesel, what happens if it gets into your fuel tank? Gunk! Another possibility is an electrical spark discharge to crack the atoms apart. This is very effective, but also expensive and difficult to maintain.

Unfortunately, even if you're able to break down the hydrocarbon into carbon, hydrogen, and oxygen, you won't be able to generate power.It requires more energy to break them apart than you would recover by burning them.

A bigger problem is pollutants which contain heavy metals. None of the above solutions will work for those, because you still have the heavy metal atoms to worry about. You would have to find a different process which can "scrub" the heavy metal pollution from the air after you burn the hydrocarbons. Heavy metals are a major source of pollution from mining and from burning coal.

Thank you for your very insightful question!

You certainly have a great idea of how to recycle chemical waste, something we dont want, and turn it into water and oxygen and energy, things we do want. The difficulty of your idea comes because it takes a large amount of energy to be break bonds in compounds to get individual atoms. As we know, energy is not that abundant or inexpensive right now either!

One example of this, which you may have heard of before, is the hydrogen fuel cell. A fuel cell is something that has the potential to be used in place of a gasoline engine because it uses hydrogen to make energy without any of the toxic byproducts produced by cars (carbon monoxide, etc). One limiting factor of fuel cells is actually getting the hydrogen to use for fuel- in this case, they split water or other hydrocarbon molecules to get the hydrogen (similar to how you suggested). However, this takes either a large amount of energy, extremely expensive materials, or both. There is a lot of research going on all over the world to try to figure out how to get hydrogen by splitting bigger molecules in an easier and less expensive manner. It is conceivable that someday, if this research progresses enough, scientists might be able to take larger molecules that are undesirable pollutants and split them into their individual atoms for positive uses!