Selective Synthesis of Acetaldehyde Using Iron Surface-Catalyzed Hydrogenation

Researchers have made significant progress in the synthesis of acetaldehyde, a versatile organic compound, using a novel approach involving iron surface-catalyzed hydrogenation of acetic acid. The study demonstrated the highly-selective synthesis of acetaldehyde by the hydrogenation of acetic acid catalyzed by the iron surface on Pd-Fe alloy nanoparticles derived from Pd/Fe2O3. This breakthrough has the potential to revolutionize the production of acetaldehyde, a key intermediate in various industrial processes.

Key Takeaways:

• The researchers used Pd-Fe alloy nanoparticles derived from Pd/Fe2O3 as the catalyst for the hydrogenation of acetic acid, demonstrating the highly-selective synthesis of acetaldehyde.
• The catalyst from Pd/Fe2O3 with low Pd loading amount provoked the deposition of carbonaceous species, including iron carbides, resulting in a low acetaldehyde yield.
• Conversely, Pd/Fe2O3 with high Pd loading amount (28-44 wt%) prevented the formation of iron carbides, leading to the formation of aldehyde in an excellent yield, maintained even after 200 h.
• Further Pd loading increased the ethanol formation, indicating the need for a balance between Pd and Fe loading.
• In situ XAFS measurements showed that the reductive pretreatment under hydrogen flow of Pd/Fe2O3 formed the core-shell type Pd-Fe alloy nanoparticles.
• The study concluded that acetic acid would convert to acetaldehyde with concomitant oxidation of the surface of the metallic iron shell, and H-2 would reduce the thus-partially oxidized shell to regenerate the initial metallic surface.

Statistics:

• 28-44 wt% Pd loading amount was required to prevent the formation of iron carbides and achieve an excellent yield of acetaldehyde.
• After 200 h, the acetaldehyde yield remained high, indicating the stability of the catalyst.
• 200 h was the duration of the reaction, during which the catalyst remained active.

Sources:

• "Catalytic Selective Hydrogenation of Acetic Acid To Acetaldehyde Over the Surface of the Iron Shell On Pd-fe Alloy Nanoparticles." Catalysis Science & Technology, 2022.
• Kyoto Institute for Technology, Faculty of Materials Science and Engineering
• Royal Soc Chemistry, Thomas Graham House, Science Park, Milton Rd, Cambridge CB4 0WF, Cambs, England.