WANG Feng and colleagues have used a typical dilute fermentation broth of Clonstridium acetobutylicum containing ABE (acetone–butanol–ethanol–water) and transformed the mixture to 4-heptanone (4-HPO), using tin-doped ceria (Sn-ceria) as a Guerbet-catalyst. Selectivity was as high as 86%. Water (up to 27 wt%), detrimental to the reported catalysts for ABE conversion, was beneficial for producing 4-HPO, highlighting the feasibility of the current reaction system. In a 300 h continuous reaction over 2 wt% Sn-ceria catalyst, the average 4-HPO selectivity was maintained at 85% with 50% conversion and > 90% carbon balance.

CAS news release, December 5, 2018