Selective Hydrodeoxygenation of Esters to Unsymmetrical Ethers over a Zirconium Oxide-Supported Pt–Mo Catalyst
Katsumasa Sakoda, Sho Yamaguchi, Takato Mitsudome, Tomoo Mizugaki
Abstract
The catalytic hydrodeoxygenation (HDO) of carbonyl oxygen in esters using H2 is an attractive method for synthesizing unsymmetrical ethers because water is theoretically the sole coproduct. Herein, we report a heterogeneous catalytic system for the selective HDO of esters to unsymmetrical ethers over a zirconium oxide-supported platinum–molybdenum catalyst (Pt–Mo/ZrO2). A wide range of esters were transformed into the corresponding unsymmetrical ethers under mild reaction conditions (0.5 MPa H2 at 100 °C). The Pt–Mo/ZrO2 catalyst was also successfully applied to the conversion of a biomass-derived triglyceride into the corresponding triether. Physicochemical characterization and control experiments revealed that cooperative catalysis between Pt nanoparticles and neighboring molybdenum oxide species on the ZrO2 surface plays a key role in the highly selective HDO of esters. This Pt–Mo/ZrO2 catalyst system offers a highly efficient strategy for synthesizing unsymmetrical ethers and broadens the scope of sustainable reaction processes.