First-Principles Microkinetic Study of the Catalytic Hydrodeoxygenation of Guaiacol on Transition Metal Surfaces

The mechanism behind the hydrodeoxygenation (HDO) of guaiacol on Co(0001), Ni(111), Cu(111), Pd(111), and Pt(111) was investigated by constructing a first-principles microkinetic model from density functional theory (DFT) models for 68 possible intermediates over each surface. We report that the most energetically favorable pathway for this process is the demethylation of guaiacol to catechol over Ni(111), which exhibits highly desirable deoxygenation and hydrogenation kinetics at industrial temperatures. Guaiacol readily undergoes hydrogenation over Pt(111) and Pd(111), but the products exhibit slow desorption from the surfaces at standard operation temperatures. Furthermore, the deoxygenation pathway is hindered by the high energy barrier associated with the scission of the Calkyl-O bond. Catalytic Hydrodeoxygenation of Guaiacol: By constructing a first-principles microkinetic model from over 300 DFT models of the intermediates, we report that guaiacol HDO exhibits highly desirable deoxygenation and hydrogenation kinetics over Ni(111) at industrial temperatures.image