Rational design of polyoxometalates/phthalocyanine cobalt hybrids: production of ethyl acetate through aerobic oxidation and self-esterification of ethanol

A series of metal-substituted polyoxometalates KnPW11MO39 (M = none, Co2+, Fe2+, Ni2+, Cu2+, Mn2+) was evaluated in oxidative esterification reactions. Then, K5PW11CoO39/phthalocyanine cobalt (PW11Co/Co-Pc) was designed to achieve the conversion of ethanol to ethyl acetate through oxidative self-esterification reaction. Synergy of redox active sites, acidic sites, electron-transferring between PW11CoO39 and phthalocyanine cobalt permitted ethanol convert into acetic ester with 91.2% selectivity at 85.1% conversion using oxygen as an oxidant. The tenth run of PW11Co/Co-Pc recycle showed only a slight decrease in the efficiency.