Reverse water-gas shift reaction in a foam electrode structure plasma catalytic reactor: Proper evaluation of the synergistic effect

Plasma catalytic reverse water-gas shift (RWGS) reaction is considered efficiently to convert CO 2 into CO for the synergistic effect between plasma and catalyst. However, this synergistic effect has long not been properly evaluated, due to the difficulty in measuring the actual catalyst temperature ( T cat ) during discharge. Herein, we report a novel foam electrode structure plasma catalytic reactor that enables real-time measurement of the central temperature ( T C ) of the foam electrode by a thermocouple during discharge. Since the catalyst is coated onto the foam electrode, T C is much closer to T cat than the commonly used wall temperature ( T W ). Based on T C , a proper evaluation of the synergistic effect is conducted by employing a synergy factor ( SF ) within 196 o C–390 o C. It is found that CO 2 conversion in plasma-catalysis is not only higher than the sum of that in plasma and thermal-catalysis individually, but also breaks the thermodynamic equilibrium limitation. Moreover, this novel reactor exhibits higher CO 2 conversion (30.0 %) for RWGS reaction compared to that in a typical packed-bed plasma catalytic reactor (19.6 %) with a same discharge power of 16.5 W and gas hourly space velocity of 12000 ml/(g·h), demonstrating its potential in the application of RWGS process.