Performance of low-content Pd and high-content Co, Ni supported on hierarchical activated carbon for the hydrotreatment of <i>Calophyllum inophyllum</i> oil (CIO)

A comparative study between a catalyst with a small amount of a noble metal, Pd/HAC, and those with large amounts of non-noble metals, Co/HAC and Ni/HAC, was conducted. Specifically, the activity and selectivity of these catalysts in the hydrotreatment of Calophyllum inophyllum oil were evaluated. The loading metal contents of Pd, Co, and Ni were 0.43, 3.310, and 4.110 wt%. Hierarchical activated carbon (HAC) was synthesized from wasted Merbau Wood through CO2 and H2O activation and used as a support for the metals. Co, Ni, and Pd were impregnated into HAC by using the wet impregnation method. HAC showed a diffraction peak at 26.46 degrees, pore size distribution of 1.356-6.160 nm, and specific surface area of 412.3 m(2) g(-1). Among the catalysts tested, Pd/HAC demonstrated the best catalytic performance, yielding 27.05 wt% liquid product (6.63 wt% gasoline; 17.6 wt% diesel oil). Impregnation of HAC with Pd enhanced catalytic properties by increasing the specific surface area to 524.0 m(2) g(-1) and acidity to 20.37 mmol g(-1).