Conversion of ethanol to 1,3-butadiene over Ag-ZrO2/SiO2 catalysts: The role of surface interfaces

A series of Ag-ZrO2/SiO2 catalysts with different metal-support interfaces were synthesized in an effort to elucidate the roles of specific interfaces in controlling the ethanol to 1,3-butadiene conversion and selectivity. According to the results of detailed characterizations (e.g. CO/pyridine-DRIFTS, XPS, TEM, NH3-TPD, and H-1 MAS NMR), it was found that the Ag-O-Si interfaces significantly enhanced the dehydrogenation of ethanol while the presence of ZrO2 improved the interaction between Ag and ZrO2 /SiO2, creating more Ae active sites. The high dispersion of ZrO2 on SiO2 generated abundant Zr-O-Si interfaces with medium and weak Lewis acidity, promoting the condensation of acetaldehyde to crotonaldehyde. These Zr-O-Si interfaces in close interaction with Ae species played a critical role in the enhanced H transfer during the MPV reduction of crotonaldehyde to crotyl alcohol. The synergies among the interfaces resulted in retarded ethanol dehydration reactivity, balanced ethanol dehydrogenation and condensation reactions, and a subsequent high 1,3-butadiene yield. (C) 2020 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.

Automated summary

The Ag-O-Si interfaces significantly enhanced the dehydrogenation of ethanol, while the Zr-O-Si interfaces promoted the condensation of acetaldehyde, leading to a high yield of 1,3-butadiene through the synergistic effects of these interfaces.