III International Conference

PP-II-70THE INFLUENCE OF PREPARATION CONDITIONS ON PHYSICOCHEMICALPROPERTIES AND CATALYTIC ACTIVITY OF Ni-Au/Al 3 CrO 6 CATALYST INPARTIAL OXIDATION OF METHANEManiecki T.P., Bawolak K., Gebauer D., JozwiakW.K.Institute of General and Ecological Chemistry, Technical University of Lodz90-924 Lodz, ul. Zeromskiego 119, Poland, tel: (+48) 46 6313125, fax: (+48) 46 6313128E-mail: kbawolak@p.lodz.plThe physicochemical properties and catalytic activity of 5% Ni/Al 3 CrO 6 and 5% Ni-2%Au/Al 3 CrO 6 catalysts were examined in dependence of preparation conditions (temperaturetreatment, pH, kind of precursors, presence of chlorine contents). Bimetallic 5% Ni-2%Au/Al 3 CrO 6 catalysts were more active and more stable than monometallic5% Ni/Al 3 CrO 6 . An addition of gold improves resistance of carbon deposition. Howeverintroduction of chloride ions AuCl 4-during impregnation step can influence on poisoningactive center of nickel-gold catalysts in partial oxidation of methane (POM).The strong interest in gold is due to its potential applicability in many low-temperaturereactions of CO oxidation [1], selective NO x reduction, water-gas shift reaction and itssuccessful using in high-temperature process, for e.g. hydrocarbon oxidation [2]. The goldaddition to Ni, Fe catalyst changes their crystalline network. This modification of surfacecauses the abatement of methane disociative adsorption and coke formation that improvestability and life time of catalysts [3]. The last researches show that nickel-gold alloying onthe surface can be a good method to controll dilution of acitve nickel sites which take part indehydrogenation of CH 3 species.The aim of this work is to determine the influence of preparation conditions onphysicochemiacal and catalytic properties of mono and bimetallic 5% Ni-2%Au/Al 3 CrO 6catalysts.The Al 2 O 3 , Cr 2 O 3 , Al 3 CrO 6 supports were prepared by precipitation and co-precipitation(Cr(NO 3 ) 3 ⋅9H 2 O and Al(NO 3 ) 3 ⋅9H 2 O) by ammonia aqueuos solution. All supports were driedand calcined at 700°C/4h/air. 5%Ni and 5%Ni-2%Au catalysts were prepared by wetimpregnation method, sequential impregnation (precursors: Ni(NO 3 ) 2 ⋅6H 2 O, HAuCl 4 andNi(NO 3 ) 2 ⋅HNO 3 , Au(NO 3 ) 3 ⋅HNO 3 ). Catalysts were dried and calcined at 400 °C/4h/air.The physicochemical properties of catalysts were investigated by TPO-TPR H2 , BET,XRD, TOC analysis. The activity tests in partial oxidation of methane were carried out in aflow quartz reactor in the temperature range 25-900 °C with GC analysis. The 24 h activity292