High-Performance and Stable Dendrite-Structured Mesoporous Zn-Zr/Dsms Catalysts for Ethanol Conversion to 1,3-Butadiene

Catalytic conversion of bio-ethanol (EtOH) into 1,3-butadiene (1,3-BD, ETB) represents a low-carbon technology contributing to the sustainable production of renewable 1,3-BD. However, the low selectivity towards 1,3-BD and poor stability of catalysts hinders practical applications of the ETB process. In this work, we presented a novel Zn-Zr catalyst supported on dendrite-structured mesoporous silica (DSMS). Compared to the typical meso- or micro- porous materials such as SBA-15, meso-SiO2 and Silicate-1 supported catalysts, the Zn-Zr/DSMS catalysts exhibited superior catalytic performance and exceptionally high stability in the ETB reaction. Over the representative 0.5%Zn2%Zr/DSMS catalyst, high selectivity of 1,3-BD > 65% and EtOH conversions of 72%-100% were obtained in a wide temperature range of 350-400 ℃. More attractively, the distinguished performance was stable in a long time on stream of 172 h, and was able to be effectively restored by calcining the spent catalyst. According to the systematic characterizations of the catalysts, the Zn and Zr species were highly dispersed on the DSMS support to exclusively form abundant Lewis acid sites, which realized exceptionally high activity and 1,3-BD selectivity over the 0.5%Zn2%Zr/DSMS catalyst. The dendrite-structured mesoporous support endowed the catalyst with high tolerance for carbonaceous deposition, greatly contributing to the catalyst high stability in the reaction. Correlated to the results of in-situ spectroscopy and conditional experiments, the catalytic roles of active sites and the reaction pathway over the Zn-Zr/DSMS catalyst were proposed for the ETB process.