Water-assisted ketonization of methyl palmitate to palmitone over metal incorporated TiO2 catalysts

Pittayatornkul, Jetsadagorn; Maluangnont, Tosapol; Jongpatiwut, Siriporn; Praserthdam, Piyasan; Ogawa, Makoto; Sooknoi, Tawan

doi:10.1039/d4re00111g

Water-assisted ketonization of methyl palmitate to palmitone over metal incorporated TiO2 catalysts

Author(s)

Pittayatornkul, Jetsadagorn

Maluangnont, Tosapol

Jongpatiwut, Siriporn

Praserthdam, Piyasan

Ogawa, Makoto

Sooknoi, Tawan

Date Issued

May 28, 2024

Type

Article

DOI

10.1039/d4re00111g

Abstract

Ketonization of methyl palmitate to palmitone, a bio-lube precursor, was investigated over noble metal (Pt, Ru, and Pd) incorporated TiO2 catalysts in the presence of water under an atmospheric H2/N2 flow. Methyl palmitate underwent hydrolysis to palmitic acid that ketonized to palmitone over Lewis Ti³⁺ sites. The water co-feeding also suppressed hydrodeoxygenation of methyl palmitate and palmitone cracking leading to high palmitone selectivity. The incorporated metals facilitated H2 dissociation/spillover on TiO2 which generated more Lewis Ti³⁺ sites for higher ketonization activity. At 400 °C, 0.5Pd/TiO2 provided ∼90% conversion with >85% palmitone selectivity and >25 h stability, due to its efficient H2 dissociation/spillover to continually recover Lewis Ti³⁺ sites. Meanwhile 0.5Pt/TiO2 promoted excessive hydrodeoxygenation, leading to the deactivation from CO poisoning at the metallic Pt sites. The findings of this study offer a sustainable approach for the selective production of bio-lube precursors from renewable fatty acid methyl esters.

Citation

Reaction Chemistry and Engineering, 9(9), 2345-2357, 2024