No. Most of these "desktop NAS" devices are tiny little things with an underpowered SOC processor, often ARM architecture, sometimes Atom, with 256MB or possibly 512MB of RAM if you're lucky. Some of the higher end rackmount appliances are built around nearly standard off-the-shelf components, and those it might be practical to run FreeNAS on, but by the time you've bought one of those, you could build two or three FreeNAS's for the same price.