Its overkill but it will work. Nothing wrong with running a huge skimmer on a small tank, just means your evaporation will likely go up slightly and you may need to watch your water levels a little more.
Edit: Is this tank sump'd? If it is I would go ahead and give it a try; cant hurt. If anything it will just turn your tank into a low nutrient system, but those minerals ect are replaced on water changes.