High yield 1-L scale synthesis of ZIF-8 via a sonochemical route

ZIF-8 was prepared using a sonochemical method under pH-adjusted synthesis conditions using NaOH (aq) with a minimal amount of triethylamine. After optimizing the synthesis parameters, it was extended successfully to 1 L-scale synthesis with an 85% product yield at a high substrate concentration (Zn2+:-DMF = 1:9.3) in 2 h without compromising the textural properties. The prepared ZIF-8 samples after pelletization demonstrating excellent catalytic activity in the Knoevenagel condensation reaction of benzaldehyde with malononitrile. (C) 2012 Elsevier Inc. All rights reserved.