An experimental apparatus was used for a batch electroplating reaction with the emulsion of a CO₂, surfactant, and the electroplating solution. The apparatus is labeled as follows: (a) CO₂ cylinder; (b) cooler; (c) high pressure pump; (d) temperature-controlled air bath; (e) reactor with magnetic stirrer; (g) trap; (f) programmable power supply; (h) gas meter; BPR: back-pressure regulator; PI: pressure indicator; TI: temperature indicator; V: valve.