Effective hydrodeoxygenation of palmitic acid to diesel-like hydrocarbons over MoO2/CNTs catalyst

• MoO2/CNTs are a novel catalyst for long-chain fatty acid deoxygenation.
• MoO2/CNTs showed superior low temperature activity and hexadecane selectivity.
• The H2 pressure of the reaction can control the product selectivity.
• MoO2/CNTs are a much better catalyst for deoxygenation of palmitic acid than Pd/CNTs.

The liquid-phase deoxygenation reaction of palmitic acid has been investigated in a batch reactor over carbon nanotubes (CNTs)-supported MoO2 and Pd catalysts under hydrogen atmosphere. The results showed that palmitic acid can be converted completely at 220 °C on MoO2/CNTs catalyst with high hexadecane selectivity (92.2%). The H2 pressure of the reaction can control the product׳s selectivity. Compared with noble metal Pd-based catalyst, MoO2-based catalyst is a much better catalyst because of its high activity, selectivity, stability and low cost. Product distribution revealed that Pd offered high selectivity for pentadecane, whereas MoO2 showed excellent selectivity for hexadecane, which showed more favorable atom efficiency. Therefore, the MoO2/CNTs catalyst can be regarded as an attractive candidate for catalytic hydrodeoxygenation of long-chain fatty acids to produce high-grade transportation biofuels.

In this work, hydrodeoxygenation of palmitic acid into C16 hydrocarbons was successfully achieved over 5 % MoO2 /CNTs catalysts at a much lower temperature (220oC). The H2 pressure of the reaction can controls the product selectivity. The low cost and high activity make the 5 % MoO2 /CNTs catalyst more competitive than Pd-based noble metals catalysts. In summary, this material described in this paper provides a new protocol to decrease the oxygen content of bio-oil, especially algae-based, for their utilization in the future. Proposed main reaction pathways for palmitic acid conversion over MoO2 /CNTs in the presence of 4Mp H2 at 220 oC. Figure optionsDownload high-quality image (211 K)Download as PowerPoint slide