Effect of Catalyst Structure and Acid–Base Property on the Multiproduct Upgrade of Ethanol and Acetaldehyde to C4 (Butadiene and Butanol) over the Y–SiO2 Catalysts

The multiproduct upgrade of ethanol and acetaldehyde to butadiene as a high-value chemical and butanol as a biofuel was investigated over the Y–SiO2 heterogeneous catalysts. The sum selectivity of butanol and butadiene is over 90% for the Y–SiO2 catalysts with Y/Si ratios from 0.05 to 0.35, while the distribution changes with the Y/Si ratio. The highest butadiene selectivity of 81.2% with a butanol selectivity of 10.3% was obtained over the Y–SiO2 catalyst with a Y/Si ratio of 0.05. To study the effect of the catalyst structure and acid–base property on catalytic performance, the Y–SiO2 catalysts with different Y/Si ratios were further comprehensively characterized by techniques including nitrogen adsorption–desorption, X-ray diffraction, X-ray photoelectron spectroscopy (XPS), 29Si cross–polarization/magic-angle spinning nuclear magnetic resonance (29Si CP MAS NMR), Fourier transform infrared resonance (FTIR), UV–Vis diffuse reflectance spectra (UV–Vis DRS), temperature-programmed desorption of NH3 and C...