Synthesis of n-butanol from ethanol over Pt-Y/beta catalyst: Synergistic catalysis of yttrium and platinum site

Conversion of ethanol to high-value alcohols is an attractive approach for developing renewable biofuels, the key is to develop stable and high-efficient catalysts. In this work, based on the preparation strategy of heteroatomic Beta zeolites, a bifunctional Pt-Y/Beta catalyst was prepared by solid-state ion exchange and impregnation. Through characterization techniques such as TEM, NMR and XAS, it was confirmed that the Y species were incorporated into the framework of Beta zeolite by interacting with the silanol groups located at the defect sites, while the Pt species were confirmed to be present on the surface of the zeolite in the form of dispersed nanoparticles. The unique structure form and the favorable spatial proximity of the two metallic active sites lead to a synergistic catalysis, which enable a one-step conversion of ethanol to n-butanol with exceptionally high selectivity of 68 %. In situ DRIFT characterization, ethanol-TPD and relay experiment results show that in the ethanol to n-butanol reaction, the Pt species in Pt-Y/Beta catalyst serves as the active center for the dehydrogenation of ethanol and the hydrogenation of crotonaldehyde and crotyl alcohol, while the Y species is responsible for catalyzing the condensation reaction of acetaldehyde.