Diatomite Stabilized KOH: An Efficient Heterogeneous Catalyst for Cyclopentanone Self-condensation

Graphical A heterogeneous catalyst (KOH/diatomite) was prepared in a simple way, and exhibited good activity (overall yield: 85.0 %). We suggest that the excellent catalytic activity of KOH/diatomite can be attributed to the formation of K−O−Si bond, the impurity elements existed in diatomite and higher BET surface areas may also benefit. Aldol condensation of cyclopentanone is an attractive reaction for bio-jet fuel production. KOH is an efficient homogeneous catalyst for aldol condensation but suffering the problem of separation. In this paper, a heterogeneous catalyst, diatomite stabilized KOH (KOH/diatomite) was prepared in a simple way (dry-mixed impregnation process), and exhibited good activity (overall yield: 85.0 %) and reusability. To clarify the support effect of diatomite, KOH/SiO 2 catalyst was also prepared. According to characterizations of these two catalysts, we suggest that the excellent catalytic activity of KOH/diatomite can be attributed to the formation of K−O−Si bond. In addition, the impurity elements existed in diatomite (e. g. CaO, Na 2 O, Al 2 O 3 ) and higher BET surface areas may also benefit to this reaction. This study provides a new possibility for converting homogeneous catalyst (KOH) to heterogeneous catalyst (KOH/diatomite). In this way, KOH/diatomite performed excellent catalytic activity and exhibited stable reusability, which can avoid the problem of separation and pollution.