abstracts - Институт катализа им. Г.К. Борескова

OP-III-30ACTIVE PHASE TRANSFORMATION ON SURFACE OF SUPPORTED Ni-Au/Al 2 O 3CATALYST DURING PARTIAL OXIDATION OF METHANE TO SYNTHESIS GASManiecki T.P., Stadnichenko A.I. 1 , Maniukiewicz W., Bawolak K., Boronin A.I. 1 ,Jóźwiak W.K.Politechnika Łódzka Instytut Chemii Ogólnej i Ekologicznej, Łódź ul. Źwirki 361 Boreskov Institute of Catalysis SB RAS, Novosibirsk, RussiaE-mail: tmanieck@mail.p.lodz.plAnnotation:This paper is focused on the phisicochemical properties and catalytic activity ofsupported Ni-Au/Al 2 O 3 catalysts partial oxidation of methane (POM). The experimentalmethods of catalyst characterization were: TPR H2 , BET(liquid N 2 ), XRD, XPS. Measurementsof catalytic activity in POM reaction were carried out under atmospheric pressure intemperature range 25-900°. The conventional wetness aqueous impregnation method has beenapplied for the preparation of bimetallic Ni-Au/Al 2 O 3 catalysts. Formation of Ni - Au alloyduring high temperature POM reaction was experimentally proved. Reduction of Ni - Aucatalyst is prerequisite condition to catalyze POM reaction. Gold addition to nickel/aluminaimproves catalyst stability and activity in POM reaction.During last years gold was extensively used for low temperature, CO and HC deepoxidation processes. However there is no literature data referring to an application of gold inhigh temperature reactions such as partial oxidation of methane (POM). This paper is focusedupon the active phase transformations, which occur on surface of Ni-Au/Al 2 O 3 catalystsduring POM process. Gold addition increases the activity and stability of supported Ni/Al 2 O 3catalysts. Such behavior can be referred to alloy formation between nickel and gold onalumina surface. In literature there is no data relevant to nickel - gold alloy formation.Catalyst preparationThe conventional wetness aqueous impregnation method has been applied for thepreparation of Ni-Au/Al 2 O 3 catalysts. As a support a commercial alumina FLUKA 507C wasused (S BET =138 m 2 /g). Two metal component catalysts containing 8%Ni - 2%Au and monometallic 10%Ni and 10%Au were prepared by co-impregnation method in an aqueoussolutions of starting compounds Ni(NO 3 ) 2 and HAuCl 4 . After drying catalysts were calcined4h in air at 400°C. For XRD studies a reference material consisting of mixture of NiO and Auwith the mutual weight ratio of Ni/Au = 4:1 was used.Methods of characterizationTemperature programmed reduction TPR H2 in 5% H 2 – 95% Ar mixture was carried outin automatic TPO-TPR system AMI-1 Altamira Instruments in temperature range 25 - 900°Cwith the linear heating rate 10°C/min. The sample mass was about 0,1g. Specific surface areaand pore volume distribution was measured with automatic sorptometer Carlo-Erba Italy.Phase composition was studied by time-resolved in situ high temperature wide-angle X-raydiffraction. Data were collected using a PANalytical X’Pert MPD diffractometer equipped386