(557c) Catalytic Deoxygenation of Guaiacol Using Methane

Guaiacol, a phenol derived compound produced by thermal degradation of lignin, represents a model compound for catalytic deoxygenation to upgrade pyrolysis bio-oils. In our prior work, with Pt/C as catalyst, such a process using H₂ was developed. Based on kinetic modeling and catalyst characterization, deactivation mechanism and reaction pathways were also proposed. To overcome the high cost of H₂, in this work, methane was used to deoxygenate guaiacol. On Pt/C catalyst, experimentally, methane was found to exhibit as good deoxygenation performance as H₂, in terms of guaiacol conversion and product distribution. Its lifetime, however, was low (~ 3 hr). After bismuth was added as a promoter, the lifetime of Pt-Bi/C was extended (no significant deactivation in 8 hrs), although catalyst performance decreased somewhat, which could be compensated by increasing reaction temperature. Further, using periodic slab-model density functional theory (DFT), computations were made to propose mechanisms for methane-deoxygenation of guaiacol and increased stability from Bi addition.