Hydrodeoxygenation of oleic acid using γ-Al2O3 supported transition metallic catalyst systems: Insight into the development of novel FeCu/γ-Al2O3 catalyst

Abstract

Hydrodeoxygenation of oleic acid was performed using NiMo-based catalyst supported on several mesoporous supports such as γ-Al2O3, SBA-15 and hexagonal mesoporous silica (HMS) in batch mode at 350−410 °C under H2 pressure of 6.9 MPa. The catalysts were synthesized using incipient wet impregnation with approximately 12 wt.% Mo and 4 wt.% Ni loadings. Among the synthesized catalysts, NiMo/SBA-15 demonstrated the highest surface area (484 m2/g) and average pore diameter (9.4 nm). Moreover, γ-Al2O3 showed better catalytic activity during hydrodeoxygenation compared to SBA-15 and HMS supports. At hydrotreating conditions (390 °C and 6.9 MPa), NiMo/γ-Al2O3 showed 77 % oxygen removal and 42 % selectivity towards C16-C18 alkanes during 8 h of batch reaction. To elucidate the promotional effects, bimetallic catalyst (NiMo/γ-Al2O3) promoted with Cu, Cr and Fe (CuNiMo/γ-Al2O3, CrNiMo/γ-Al2O3 and FeNiMo/γ-Al2O3) catalysts were used for hydrodeoxygenation of oleic acid. CuNiMo/γ-Al2O3 gave the highest conversion (ca. 92 %) during hydrodeoxygenation at 300 °C, 6.9 MPa H2 pressure and 600 rpm agitation speed.