abstracts - Институт катализа им. Г.К. Борескова

OP-I-9NICKEL EFFECT ON COMPONENTS STATE AND HDS ACTIVITY IN ALUMINASUPPORTED HETEROPOLYTUNGSTATESPalcheva R., Spojakina A., Petrov L.Institute of Catalysis, Bulgarian Academy of Sciences, Sofia, BulgariaE-mail: kiyky@ic.bas.bgTungsten containing catalysts are used extensively in important hydrotreating processesincluding hydrodesulfurization (HDS) of oils. These processes play an essential role in theproduction of environmentally friendly fuels. The strict environmental regulations are thedriving force for development of more active catalysts. Identification of the active phases is avery important to prepare catalysts with the optimal concentration of suitable components. Itwas shown that hydrodesulfurization activity of NiW catalysts is related with the nickeltungsteninteraction phase formation. In this aspect the heteropolycompounds are especiallyinteresting for preparation of hydrotreating catalysts because they contain both fundamentaland promoting elements (heteropoly anion and countercation) in a single compound ofdefined structure.The nickel effect on the HDS activity of catalyst prepared using the tungstophosphoricacid (TPA) demands special attention because nickel is known as the best promotor in the W-containing hydrotreating catalysts.Here the influence of the Ni concentration and the preparation conditions of the aluminasupported NiW catalysts modelled using TPA, its Ni salt and Ni(NO) 3 salt on theircomponents state and HDS activity has been examined.The catalysts have been prepared by incipient wetness impregnation of alumina withaqueous solution of TPA (HPW) and its Ni salt (NiPW). The Ni content is varied usingprevious loading of the Ni(NO 3 ) 2 salt solution on the support. The catalysts were dried at120 o C 4h and calcined at 400 o C 2h. The loaded tungsten and nickel are about 19 wt.% and 1-4.5 wt. %, respectively.The samples are characterized by BET, IR, and XPS methods. The thiophene conversionin C 4 -hydrocarbons at 350 o C was used to evaluate the HDS activity of the catalysts. Thecalcined catalyst were pretreated 1h with H 2 S at 400 o C prior to catalyst test. After activationthe catalysts were flushed with argon and feeding with the reaction mixture of thiophene(6 vol. %) and hydrogen.The IR spectrum of the acid supported on alumina (HPW) compared to the spectrum ofthe TPA shows that initial compound is destroyed partially: the characteristic bands decrease90