(193d) Exploring Transition Metal Carbides and Phosphides for Ex-Situ Catalytic Fast Pyrolysis

Hexagonal Fe₂N type molybdenum carbide (β-Mo₂C) has been explored as biomass upgrading catalyst in recent decades for model compounds via hydrodesulfurization (HDS), hydrodenitrogenation (HDN), and hydrodeoxygenation (HDO). Molybdenum carbide has also been shown to be a superior catalyst support, for example, for platinum in comparison to carbon in electrocatalytic water splitting. However, there have not been any studies to investigate the effects of supporting biomass upgrading catalysts such as nickel phosphide (Ni₂P) on molybdenum carbide. Additional carbide-phosphide interfacial sites thus generated have the potential to be of tremendous importance in biomass conversion catalysis. One of the main stumbling blocks for biomass derived pyrolysis oils finding wider use in energy and chemical feedstock generation is the presence of significant amount of oxygen, unlike in fossil reserves. While model compound studies using phosphide and carbides have shown encouraging HDO activities, only a limited number of studies have explored the HDO catalysis on abundant biopolymers such as lignin and cellulose. This presentation will be based on the ex situ catalytic fast pyrolysis of lignin and cellulose in the presence of molybdenum carbide supported nickel phosphide. Particular emphasis will be devoted to the characterization of the interfacial sites and the effect of different Ni₂P loadings on catalysis. Stability of the carbide support during the synthesis of the composite material will also be discussed. In addition, a detailed analysis of product fragments that originate due to the presence of interfacial catalyst sites will be presented via comparison with catalysis results from Mo₂C and Ni₂P individually.