Insights into the synergistic effect of active centers over ZnMg/SBA-15 catalysts in direct synthesis of butadiene from ethanol

Functionalized catalysts with multiple active centers have been studied in direct conversion of ethanol to butadiene (ETB). However, it is still a considerable challenge to control the synergistic effect of multiple active centers. Here, we report that a series of ZnMg/SBA-15-based catalysts were synthesized for the direct ETB process. The non-polar solvent n-hexane is utilized to improve the synergistic effects of ZnO, MgO and SBA-15. The characterization results demonstrate that the ZnMg/SBA-15-hexane catalyst, prepared from n-hexane solvent, can increase dehydrogenation activity and promote synergistic catalysis. The direct ETB performance reveals that it exhibits an excellent selectivity of 70% towards the butadiene product. Further, our in situ DRIFTS analysis indicates that aldol condensation and the MPV reaction are the rate-determining steps of the direct ETB process. The present work offers a simple strategy to optimize synergies of multiple active centers.