Manufacture of olefins by the selective hydrodeoxygenation of lignocellulosic ketones over a cobalt molybdate catalyst

Abstract

Olefins are important feedstocks in the production of fuels and many useful chemicals. Herein, cobalt molybdate (CoMoO₄) was first synthesized by an environmentally friendly evaporation method and it exhibited excellent catalytic performance for the production of olefins by the selective hydrodeoxygenation (HDO) of ketones that can be derived from lignocellulose. On the basis of the characterization results, the excellent catalytic performance of CoMoO₄ was attributed to its larger specific surface area, better pore structure, higher oxygen vacancy (or Mo⁵⁺ species) concentration, higher acid strength and higher concentration of acid sites. Under the optimized reaction conditions, 4-heptanone was almost completely converted to heptene, and a high carbon yield of heptene (96%) was achieved over a CoMoO₄ catalyst with a Co/Mo atomic ratio of 0.8 (denoted as CoMoO₄-0.8). The CoMoO₄ catalyst is also active for the selective HDO of other lignocellulosic ketones (such as acetone, butanone, 2-pentanone, 3-pentanone, cyclopentanone, cyclohexanone, 5-nonanone and acetophenone) to their corresponding olefins.