Applied Catalysis A: General 441–442 (2012) 99–107 Contents lists available at SciVerse ScienceDirect Applied Catalysis A: General j ourna l ho me page: www.elsevier.com/locate/apcata Preparation and evaluation of hydrotreating catalysts based on activated carbon derived from oil sand petroleum coke Yu Shi a,∗ , Jinwen Chen a , Jian Chen b , Robb A. Macleod b , Marek Malac b a Natural Resources Canada, CanmetENERGY-Devon, One Oil Patch Drive, Devon, AB, T9G 1A8, Canada b National Institute for Nanotechnology, National Research Council Canada, 11421 Saskatchewan Drive, Edmonton, AB, T6G 2M9, Canada a r t i c l e i n f o Article history: Received 19 May 2012 Received in revised form 13 July 2012 Accepted 14 July 2012 Available online 20 July 2012 Keywords: Oil sand petroleum (OSP) coke Activated carbon (AC) Hydrotreating Heavy vacuum gas oil (HVGO) a b s t r a c t Novel Ni–Mo/activated carbon (AC) hydrotreating catalysts were prepared and evaluated for upgrading heavy vacuum gas oil (HVGO). The AC supports were derived from Alberta oil sand petroleum coke, i.e. fluid coke and/or delayed coke, hereafter referred to as OSP coke, through a chemical process. The BET surface area was as high as 2194 m 2 /g for the fluid coke derived AC and 2357 m 2 /g for the delayed coke derived AC. Both ACs contained a large number of micropores with pore volume as high as 1.2 cm 3 /g. Ni and Mo based active component precursors could be easily loaded on the activated carbon supports by chemical impregnation of nickel nitrate and ammonium molybdate followed by calcination in nitrogen at 773 K without further modification or oxidation treatment to the activated carbons. Scanning electron microscopy (SEM) observation showed highly porous surface structure of the bare activated carbon sup- ports and well dispersed metal (oxide) precursor nanoparticles of 30–50 nm loaded on the AC supports. For comparison, two reference catalysts were also prepared by the same procedure but using commercial activated carbon and porous alumina as supports. After catalyst activation by sulfiding, the hydrotreating performance of the prepared catalysts was evaluated in a magnetically stirred autoclave with a HVGO feedstock to examine their hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) activities. Two commercial hydrotreating catalysts were also tested and compared under similar conditions with the same feed. The results showed that the catalysts based on the activated carbon supports prepared from OSP coke had better hydrotreating performance than the other catalysts. Scanning transmission elec- tron microscopy (STEM) characterization of the catalysts after activation showed that small particles of nanostructure (2–5 nm in size) were evenly embedded in the carbon matrix except for some bigger par- ticles that were located on the catalyst surface. Energy dispersive X-ray (EDX) spectroscopy revealed that these particles were composed of Ni, Mo and S elements. The dispersed nanoparticles formed the active sites and were responsible for the observed high HDS and HDN activity. Elemental analysis and surface characterization of the spent catalysts showed that the formation of coke precursors was favored on the alumina supported catalyst, which resulted in catalyst deactivation. Crown Copyright © 2012 Published by Elsevier B.V. All rights reserved. 1. Introduction As the world remaining accessible crude oil become heavier and more sour, there is an urgent need for improved technolo- gies to process such crudes to produce clean transportation fuels [1]. Catalytic hydroprocessing technology is well established in conventional refineries worldwide. Due to the high contents of sulfur, nitrogen, asphaltenes and heavy metals (nickel and vana- dium) in heavy feedstocks [2], existing catalysts and technologies have to be modified or new ones have to be developed to keep pace with more stringent environmental regulations, including ∗ Corresponding author. Tel.: +1 780 987 8703; fax: +1 780 987 5349. E-mail address: YuShi@dal.ca (Y. Shi). emissions from hydrocarbon fuel use, such as SO x , NO x , and CO 2 [3,4]. Hydrotreating catalysts are used in refineries to catalytically remove S, N and metals, and to saturate aromatic compounds. Cur- rently, alumina-supported hydrotreating catalysts are commonly used because of the good mechanical and textural specifics of alu- mina [5,6]. However, sulfidation of alumina supported metal oxides is always incomplete due to the strong metal–support interactions (SMSI) present in the catalyst sulfidation step, which is a signif- icant drawback of alumina [7–9]. In addition, alumina supported catalysts suffer from deactivation caused by coking and nitrogen compounds, and heavy metal deposition when heavy oil is treated [2,10–14]. In the past decades much effort has been paid either to modify existing catalysts by developing new synthesis meth- ods through addition of new promoting species, or to develop new supports based catalysts to improve hydrotreating performance for heavy feedstocks [15–20]. 0926-860X/$ – see front matter Crown Copyright © 2012 Published by Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.apcata.2012.07.014