Selective Hydrodeoxygenation of Alkyl Lactates to Alkyl Propionates with Fe-based Bimetallic Supported Catalysts.

Hydrodeoxygenation (HDO) of methyl lactate (ML) to methyl propionate (MP) was performed with various base-metal supported catalysts. A high yield of 77 % MP was obtained with bimetallic Fe-Ni/ZrO ₂ in methanol at 220 °C and 50 bar H ₂ . A synergistic effect of Ni increased the yield of MP significantly when using Fe-Ni/ZrO ₂ instead of Fe/ZrO ₂ alone. Moreover, the ZrO ₂ support contributed to improve the yield as a phase transition of ZrO ₂ from tetragonal to monoclinic occurred after metal doping giving rise to fine dispersion of the Fe and Ni on the ZrO ₂ , resulting in a higher catalytic activity of the material. Interestingly, it was observed that Fe-Ni/ZrO ₂ also effectively catalyzed methanol reforming to produce H ₂ in situ, followed by HDO of ML, yielding 60 % MP at 220 °C with 50 bar N ₂ instead of H ₂ . Fe-Ni/ZrO ₂ also catalyzed HDO of other short-chain alkyl lactates to the corresponding alkyl propionates in high yields around 70 %. No loss of activity of Fe-Ni/ZrO ₂ occurred in five consecutive reaction runs demonstrating the high durability of the catalyst system.
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