A reactor for coating particles includes one or more motors, a rotary vacuum chamber configured to hold particles to be coated, wherein the rotary vacuum chamber is coupled to the motors, a controller configured to cause the motors to rotate the rotary vacuum chamber about an axial axis of the rotary vacuum chamber such that the particles undergo tumbling agitation, a vacuum port to exhaust gas from the rotary vacuum chamber, a paddle assembly including a rotatable drive shaft extending through the rotary vacuum chamber and coupled to the motors and at least one paddle extending radially from the drive shaft, such that rotation of the drive shaft by the motors orbits the paddle about the drive shaft in a second direction, and a chemical delivery system including a gas outlet on the paddle configured inject process gas into the particles.

A thermochemical gas splitting reactor system and a method of splitting gas are disclosed. The system includes a reactor including a reaction zone comprising active material, a gas heating zone, and a gas distribution plate assembly interposed between the reaction zone and the gas heating zone. Exemplary systems can include multiple reactors. The method can include providing one or more reactors and performing one or more of an oxidation and/or reduction process using each of the reactors.