Like the thrusters on Mercury? They were hydrogen peroxide monopropellent?
Yes. Cold-gas propellant is basically WALL-E with the fire extinguisher. Dirt-simple to make and fly, especially for small satellites. And extremely reliable. But you don't get much from your tank of prepressurized gas.
Most hydrogen peroxide motors are the catalyzed type. As you've noticed from the bubbles, the extra oxygen pops off easily and releases energy as a result. That's the reaction you want, but you want it to happen much, much faster and thereby increase the rate of energy release. You use pure H
2O
2 (not the highly-diluted mixture you buy at the druggist/chemist), and you spray it across a plate or through a screen made of some transition metal (often platinum or silver) and the decomposition reaction rate ramps up to useful levels. This is dirt-simple too, but it's that really nice potting-soil kind of dirt. Mechanically speaking its just as reliable as cold gas. But you typically want very, very pure catalysts. And the platinum ones are costly.
The hypergols are problematic because the very properties that make them useful as propellants -- chiefly their reactivity -- are the ones that cause problems with handling or system engineering. The Apollo ELS lost a parachute on Apollo 15 because the RCS hot-fire safing procedure burned through a shroud. That in-flight safing procedure was made desirable by the difficulty in handling a fueled CM after splashdown.
Even so, you can never fully empty a propellant feed system simply by running it to fuel "depletion" because the limitations of tanking and plumbing mean some residue always remains. And one of the post-landing CM safing crews suffered injury from just the very little bit of hypergols remaining in the CM RCS. That stuff is just plain
evil. I think USAF lost a missile crew or two due to propellant leaks or tanking/detanking mishaps.
Finding propellant formulations that are energetic without being viciously toxic, and which let us have simple, reliable engines is why rocket science is still a going concern.