Not only decent performance but the highest head capacity of all liquids, and it’s boiling point can be easily adjusted by lowering pressure if required.
Einstein refrigerator: https://en.wikipedia.org/wiki/Einstein_refrigerator
The principle is still used in some refrigerating devices (typically hotel mini fridges and similar small units for RV's) as there is no need of a compressor (i.e. the device is completely silent) and also in some HVAC machines.
Ammonia has lower heat capacity than water, and it’s nasty.
You’re probably confusing gaseous ammonia, but the GGP said “of all liquids.” Liquid ammonia has a higher heat capacity than liquid water. Refrigeration is just an engineering application of the heat capacity of a working fluid (and I’ll let you guys why some of the earliest heat pumps used ammonia)
>it’s nasty
I clearly stated toxicity as an obvious downside.