I was actually researching the same thing recently after seeing 80 PLUS having better efficiency on 230V

An electric dryer / stove socket would likely be NEMA 14 in newer homes, where there are two 120V lines with 180 degree phase difference, creating 240V.  Older homes would use NEMA 10.

I found these adapters which are meant for electric vehicle charging.  Then you could use a rackmount cable to connect to the PSU.

What's been stopping me is that the 2% gain in efficiency is only worth it if you are drawing a lot of power, having to put the machine in a specific room or pay an electrician to wire another socket to the room you want.