Influential properties of activated carbon on dispersion of nickel phosphides and catalytic performance in hydrodeoxygenation of palm oil

Carbon-oxygen ratios (C/O) in activated carbon (AC) derived from wood are usually dependent upon carbonization conditions. Such a ratio directly correlates with the hydrophobicity and hydrophilicity of AC. In this work, we use two different types of AC, which are prepared by carbonization of Lead tree wood charcoal in a tube furnace (AC_TF) and Iwasaki kiln (AC_IW), as a support for nickel phosphide (NiP) for catalytic hydrodeoxygenation (HDO) of palm oil to produce green diesel. Basically, AC_IW has a higher C/O ratio than that of AC_TF. This makes the surface of AC_IW more hydrophobic. Both AC_IW and AC_TF have a great influence on the dispersion and the acid property of Ni2P. The Ni2P nanoparticles disperse mainly outside the micropores of AC_IW, whereas those on AC_TF mainly appear inside the micropores. Interestingly, NiP/AC_IW outperforms NiP/AC_TF in HDO, with an impressive green diesel yield of 98.3 %, more than three times higher than that from NiP/AC_TF. The superior HDO performance of NiP/AC_IW could be attributed to the eased accessibility of reactants to the active sites. This obtained catalyst could have high potential application in an industrial scale due to the facile preparation method, low-cost materials, large-scale production, super catalytic activity.

Automated summary

In this study, it was found that the carbon-oxygen ratio of activated carbon derived from wood affects its hydrophobicity, which in turn influences the catalytic performance of nickel phosphide for hydrodeoxygenation of palm oil. The AC derived from Lead tree wood charcoal prepared in Iwasaki kiln showed superior performance compared to that prepared in a tube furnace, with a green diesel yield of 98.3%. The dispersion of Ni2P nanoparticles, as well as the acid properties of the AC, play important roles in the catalytic activity of the system.