▎ 摘　　要

As fuel additives, ethyl levulinate (EL) can be used up to 5wt% directly in the regular diesel engines, which can overcome the limited stock of fossil fuels and reduce the environment pollutions to some extent. In this work, the three-dimensional porous hybrids consisting of SiO2 and graphene aerogel, which are denoted as SiO2@GA, are facilely assembled and used as supports for H3PW12O40 (HPW)-based solid acid catalysts. Structural analysis confirms that the resultant HPW/SiO2@GA catalysts possess unique porous structure (S(BET)257m(2)g(-1), V(p)0.450cm(3)g(-1)) and exhibit excellent catalytic performance in the synthesis of EL by the esterification of levulinic acid (LA) with ethanol. The conversion of LA can be as high as 92.4% under the reaction conditions. Furthermore, various catalytic reaction parameters are also optimized over the 10wt.% HPW/SiO2@GA catalysts, which exhibit the highest turnover frequency (TOF=83.91mmolg(-1)h(-1)) among the resultant catalysts. The results confirm the promising application of the HPW/SiO2@GA heterogeneous catalysts in the synthesis of biofuel.