Reverse Microemulsion-Synthesized High-Surface-Area Cu/γ-Al₂O₃ Catalyst for CO₂ Conversion via Reverse Water Gas...

Reverse microemulsion method was implemented to synthesize a CuO/γ-Al₂O₃ catalyst (18 wt % Cu) with a specific surface area (SSA) of 328 m²/g (after calcination at 400 °C). Catalytic performance was evaluated in the range of temperatures and space velocities (300-600 °C and 10,000-200,000 mL/(g h)). The catalyst was 100% selective to CO generation while attaining a nearly equilibrium CO₂ conversion at 500 °C (ca. 50% at 10,000 mL/(g h) and H₂/CO₂ = 4). Despite the initial reduction of surface area under the reaction conditions, the reduced Cu/γ-Al₂O₃ catalyst demonstrated a stable performance for 80 h on stream, attaining a nearly equilibrium CO₂ conversion at 600 °C (ca. 60% at 60,000 mL/(g h) and H₂/CO₂ = 4). The selectivity to CO generation remained complete during the stability test, and no significant carbon deposition was detected.