Selective Analytical Production of 1-Hydroxy-3,6-dioxabicyclo[3.2.1]octan-2-one from Catalytic Fast Pyrolysis of Cellulose with Zinc-Aluminium Layered Double Oxide Catalyst

Zinc-aluminium layered double oxide (Zn-Al-LDO) catalysts derived from layered double hydroxides (LDHs) were prepared and used for the catalytic fast pyrolysis of cellulose to selectively produce 1-hydroxy-3,6-dioxabicyclo[3.2.1]octan-2-one (LAC), which is a valuable anhydrosugar derivative. Analytical pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) experiments were performed to investigate the LAC production under different reaction conditions. The results indicated that the Zn-Al-LDO catalysts were capable of greatly inhibiting the pyrolytic formation of levoglucosan (LG) and capable of promoting the formation of LAC and certain other products. The catalyst with the Zn/Al molar ratio of 2 exhibited the best catalytic capacity for LAC production. Both pyrolysis temperature and the catalyst-to-cellulose ratio affected the pyrolytic product distribution remarkably. The maximal LAC yield was obtained at the pyrolysis temperature of 350 °C and catalyst-to-cellulose ratio of 4 and featured a peak area percentage of 21.9% (calculated by GC/MS), compared with only 3.0% from the non-catalytic process. In addition, the LDO catalyst performed better than the previously reported montmorillonite K-10 catalyst on the enhancement of LAC production.