Screening of Mixed-Metal Oxide Species for Catalytic Ex Situ Vapor-Phase Deoxygenation of Cellulose by py-GC/MS Coupled with Multivariate Analysis

We present an investigation related to catalytic upgrading of cellulose pyrolysis vapors using mixed-metal oxide catalysts derived from layered double hydroxide precursors. We performed principal component analysis on the pyrolysis-gas chromatography/mass spectrometry data to elucidate changes in the product slate between noncatalytic fast pyrolysis, catalytic pyrolysis using the oxides of magnesium, aluminum, and zinc, and catalytic pyrolysis using our synthesized mixed-metal oxides containing the same cations. Our investigations demonstrate that the mixed-metal species behave differently than even a physical mixture of their monometal counterparts, and that they are capable of producing more furanic compounds by fast pyrolysis of cellulose. We also demonstrate that the metal ratio and identity in these catalysts impart different selectivities to the resulting product slates. Taken together, these data establish the utility of the mixed-metal oxide catalysts in producing a liquid product with low oxygen content and properties that are potentially tunable by metal ion substitutions.