Hydrodeoxygenation (HDO) of triglycerides into hydrocarbons is a novel catalytic process for the production
of green biofuels. In this work, the HDO reaction mechanism over Rh/ZrO2 catalyst was studied
by selecting methyl palmitate as a model compound. HDO of methyl palmitate proceeded initially via the
hydrogenolysis into palmitic acid intermediate, followed by sequential hydrogenation-decarbonylation
reaction into pentadecane via aldehyde intermediate. Bifunctional mechanism of the Rh/ZrO2 catalyst is
advocated for the HDO process, in which both Rh sites and oxygen vacancy sites on ZrO2 synergistically
contribute to the catalysis. The interface between Rh nanoparticle and support was proposed to host the
most active sites. Based on our earlier work, a surface reaction mechanism was proposed and slightly
modified to develop a set of mechanistic kinetic models. The mechanistic model consisting of two distinct
types of adsorption sites for oxygenated components and H2, gave a good fitting to the kinetic data over
a broad range of reaction conditions and conversion levels.
©