Most likely it should work just fine, and that's solely based on my experience level. I did some quick napkin research and found some articles about this exact box loaded with FreeNAS so I can assume that it should just work. Just make sure it follows the basic FreeNAS rules:
- 8GB of RAM
- +1 GB of RAM per 1TB of storage you add
- Look up some of the features you plan on using and make sure this system has the hardware capabilities to do so.
Otherwise, yeah it should run FreeNAS.