Steelrising

You will need 4 Lavoisier Catalysts and 4 Lavoisier Sublimators to upgrade your Burette fully. Catalysts add doses of the Burette and Sublimators improve its healing effect.

Catalysts
Saint-Cloud: after finding the compass and sliding down a hill, you’ll reach a Vestal. In this new area there’s also a well. Behind the well is a chest.

Luxembourg: When you get to the temple-looking building shortly after the beginning of the district, you should see a big Ice Squire automat standing all alone in the distance. Look above him to find a hook point. From here, follow the mandatory path that will lead you to this chest.

Tuileries: right before Mirabeau’s house is a small square with an Acolyte and two Musketeer automats. By some wooden barrels is this chest.

Bastille: on the ramparts of the Bastille, by a giant gilded cannon.

Sublimators
Les Invalides: when you get to the Factory Port, immediately to your left.

La Cité: after picking up the ring (story-related) and interacting with the Vestal, drop down the broken bridge to find the chest.

Montmartre: inside the quarry. Eventually you’ll get to a big open area where in the middle are two Arachnids and one Ram. The only way forward then is through a gate you need to kick open. Then, kick open a second gate and you’ll be at a fork. Don’t go down the hill just yet. Instead, take the road that goes up until you get to some wooden scaffoldings. At the very bottom of these is the chest.

Versailles: continue down the main path after reaching the third Vestal and you’ll eventually reach a small amphitheater. The chest is at the top of the seating area, straight ahead from where you came in.

If you miss any of these, they become purchasable for 10,000 Essence each in New Game+.

credit to FranciRoosters at PowerPyx for the text descriptions.