(557b) Bifunctional Polyoxometalates for the Combined Hydrodeoxygenation and Alkylation Reactions to Upgrade Pyrolysis Oil

Bifunctional Polyoxometalates for
the Combined Hydrodeoxygenation and Alkylation Reactions to Upgrade Pyrolysis
Oil

E.
Anderson, A. Crisci, K. Murugappan and Y. Román-Leshkov

Department
of Chemical Engineering Massachusetts Institute of Technology 77 Massachusetts
Avenue, Cambridge, MA 02139 (USA)

E-mail:
yroman@mit.edu

Pyrolysis oil contains a variety of
phenols, phenolic methyl ethers and small oxygenates that must be selectively
deoxygenated before use as a high-value fuel additive. Traditional hydrodeoxgyenation catalysts, such as transition metal
oxides and platinum group metals, convert phenolic methyl ethers and other
small oxygenates into light gases, coke, or fully saturate the aromatic compounds.
Here, we will show that bifunctional polyoxometalate catalyst
selectively deoxygenate and alkylate anisole into alkylated benzenes.  A 56 % selectivity for alkylated aromatics at
a 75 % anisole conversion was observed over 16 hours on stream with minimal
deactivation. Furthermore, it was demonstrated that small oxygenates such as
acetic acid can also be deoxygenated and coupled to form alkylated aromatics. The
active acid sites were probed thorough detailed kinetic studies coupled with materials
characterization leading to the identification of a potential reaction
mechanism. These catalysts offer a strategy to simultaneously deoxygenate and
upgrade bio-oil components.

Figure 1. Product distribution (C-mol %) for the reaction of anisole (200 μL/hr) over a bifunctional polyoxometallate catalyst on TiO₂ (10 %; 300 mg)
at 320 °C with 1 Atm of hydrogen (70 mL/min). Inset
(a) and (b) display the percent distribution of alkylated oxygenates and
alkylated aromatics, respectively. Products described as ?Other? are
cyclohexene and dimethylether.