Boreskov Institute of Catalysis of the Siberian Branch of Russian ...

PP-IV-26MCM-41-SUPPORTED PdNi CATALYSTS FOR DRY REFORMINGOF METHANEK. Arishtirova 1 , C. Sener 2 , B. Pawelec 3 , T. Dogu 2 , G. Dogu 4 , J.L.G. Fierro 3 ,S. Damyanova 11Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria2 Department of Chemical Engineering, METU, 06531 Ankara, Turkey3 Instituto de Catalisis y Petroleoquimica, CSIC, Cantoblanco, Madrid, Spain4 Department of Chemical Engineering, Gazi University, 06531 Ankara, TurkeyThe reforming of methane with carbon dioxide (dry reforming) offers an alternative wayto produce hydrogen, efficient and low cost energy fuel. This reaction has received muchinterest from environmental point of view because of the possibility to reduce CO 2 andmethane emissions as both gases are contributors to the greenhouse effect. Nickel-basedcatalysts have been proved to be the most suitable catalysts due to their high activity, lowprice and inherent availability. The addition of small amount of noble metal prevents their fastdeactivation caused by coke deposition on the active nickel phase [1]. The aim of the work isto investigate the effect of the Ni/noble metal ratio on the surface and catalytic properties ofPdNi/MCM-41 catalysts in the reaction of dry methane reforming.MCM-41 obtained by hydrothermal synthesis was used as carrier for catalysts.Monometallic Ni/MCM-41 and bimetallic PdNi/MCM-41 with Ni/Si ratio of 0.2, 0.3 and 0.4were obtained by impregnation technique. Pd content was about 0.6 wt%. The samples werecharacterized by N 2 isotherms, XRD, TPR, XPS and catalytic test.The introduction of Pd into monometallic Ni catalyst leads to increase in the conversionsof CH 4 and CO 2 (Table 1). The activity of the bimetallic PdNi catalysts depends of the nickelcontent. Maximum conversions of CH 4 and CO 2 are obtained for sample with ratio Ni/Si=0.3.The H 2 /CO ratio is lower than 1, which is an indication of the occurrence of reverse water gasshift reaction. The addition of Pd into Ni/MCM-41 changes the catalytic behavior of thecatalysts with time-on-stream. Bimetallic PdNi catalysts are more stable than monometallicNi catalyst..XRD analysis showed that the structure of MCM-41 was retained in all supportedcatalysts. The addition of Pd into Ni containing catalyst provokes a decrease of the NiO sizeand S BET surface area compared to that of Pd-free Ni sample. PdNi catalyst with Ni/Si ratio of0.3 possesses the smallest nanosized NiO particles (Table 1).442