Highly Efficient Process for the Conversion of Glycerol to Acrylic Acid via Gas Phase Catalytic Oxidation of an Allyl Alcohol Intermediate

The conversion of glycerol, the main byproduct of the biodiesel industry, to acrylic acid is one of the most attractive biomass to biochemical processes. It represents millions of tons of market demand. The previous tandem reaction protocol for the conversion of glycerol to acrylic acid via an acrolein intermediate always suffers from fast catalyst deactivation and thus cannot be commercialized. Herein, a novel two-step protocol for the conversion of glycerol to acrylic acid is presented: glycerol deoxydehydration (DODH) by formic acid to allyl alcohol, followed by oxidation to acrylic acid in the gas phase over Mo–V–W–O catalysts. In the second step, supported and unsupported Mo–V–W–O multiple-metal oxide catalysts were used for the transformation of allyl alcohol to acrylic acid and excellent activity as well as selectivity was achieved. Remarkably, the mesoporous silica-supported Mo–V–W–O catalysts showed superb stability on time stream under the optimal reaction conditions with an overall acrylic acid yield of 80%. This study provides a prominent catalytic process for the large scale production of acrylic acid from biorenewable glycerol.