Glycerol valorization: The effect of Cu on the HZSM5 catalyst structure and increased selectivity towards allyl alcohol

The valorization of glycerol modified with impregnated Cu nanoparticles was investigated. Significant enhancement in the rate of formation and yield of the allyl alcohol and acrolein is observed in the gas-phase conversion of glycerol. Concerning characterization results, Cu showed low interaction with the ZSM-5 support, resulting in minor changes in the structure of materials. ZSM-5 samples showed higher selectivity to acrolein and the CuZSM-5 ones showed higher selectivity to allyl alcohol. Due to agglomeration of Cu clusters and, consequently, conversion of Cu2+ into Cu0 species during glycerol reaction, liquid product selectivity was shifted from acrolein to allyl alcohol. Analysis of the glycerol valorization of the studied processes shows that the CuZSM-5 zeolite catalyst has greater selectivity for allyl alcohol, also has better performance in terms of added value than HZSM-5 catalyst, since allyl alcohol has a higher market value than acrolein.