Application of microimpinging stream reactor coupled with ultrasound in Cu/CeZrOx solid solution catalyst preparation for CO2 hydrogenation to methanol

CO2 hydrogenation to methanol process could effectively eliminate CO2 emissions and convert CO2 into different chemicals with H2 produced via green energy. However, the catalysts for the CO2 hydrogenation process suffer from lower CO2 conversion, methanol selectivity, and deactivation. In this study, Cu/CeZrOx solid solution catalyst is prepared (Cu/CeZrOx-M) via a new microimpinging stream reactor coupled with ultrasound. Due to its better micromixing efficiency, the Cu/CeZrOx-M catalyst has smaller particle size and larger BET surface area than that prepared via the conventional batch method (Cu/CeZrOx-B). The Cu/CeZrOx-M catalyst exhibits a higher methanol STY of 222.4 gMeOH/kgcat/h with CO2 conversion of 4.67% and methanol selectivity of 55.6% at 240 °C, and possesses better stability. Combined with the characterizations of structural and electronic state, catalytic higher performance is attributed to the synergistic effect between the oxygen vacancies and higher ratio of Cu⁺. In-situ DRIFTS reveals that the Cu/CeZrOx-M catalyst follows the formate-intermediated pathway, effectively transferring the formate intermediate into methanol. Furthermore, the microimpinging stream reactor could achieve the precursor solution transmission rate with 10 mL/s. This work provides a novel method for the high-performance catalyst preparation and its mechanism study gives a deep insight into high-performance catalysts development via the bottom-up study.