For those bikes that have a front derailleur mount on the seat tube that the derailleur directly bolts to instead of using a circular clamp to hold the derailleur to the seat tube, they make some rather expensive chain catchers that bolt directly to that frame mounted fitting.

The graphic below is a copy I saved to my hard drive in 2011, I saw this in an article about bikes at a race and it said that some mechanic apparently dreamed up a chain catcher that was made from a stiff piece of wire or maybe a small diameter rod. A friend of mine had a bike with that type of front derailleur mount, so I saved that graphic at that time to show him.



It was very soon after that when a wide variety of expensive ones appeared on the market that served the same exact purpose as that piece of stiff wire. (Perhaps that mechanic should have patented his invention?)

If your seat tube is not circular or an unusual larger size, that could be another option if you have that frame mounted fitting to mount the derailleur to.