Tuning of acid/base functionalities in MgO-based Catalysts for Sustainable Ethanol Conversion to n-Butanol and Butadiene

The catalytic upgrading of ethanol to n-butanol and butadiene offers a potentially sustainable method for producing platform molecules. These processes involve complex reaction pathways that require finely tuned catalysts to minimize unwanted byproducts. Despite significant research, the roles of active sites in regulating key mechanisms remain uncertain. This study focuses on mixed metal oxide catalysts, MgAlO for n-butanol and MgSiO2 for butadiene, to investigate how catalyst composition modifications influence product formation. Through reaction activity tests, in situ FTIR spectroscopy, thermogravimetric analysis, and active site titration, correlations were established between catalyst configuration and performance. Results demonstrate that butanol formation over MgAlO correlates with the density of strong basic sites, whereas butadiene formation depends more on acid-base pair interactions. Although the reaction pathways are similar, the differing roles of active sites provide critical insights for optimizing catalysts to enhance the efficiency and selectivity of ethanol upgrading processes.