(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.