MORE ACTIVE AND SULFUR RESISTANT BIMETALLIC Pd-Ni CATALYSTS

Quimica nova

Betti, Carolina¹  Carrara, Nicolás² 

[1] Instituto de Investigaciones en Catálisis y Petroquímica, Santa Fe, Argentina;Universidad Nacional del Litoral, Santa Fe, Argentina

关键词: selective hydrogenation;    bimetallic catalysts;    sulfur resistance;    palladium;    nickel.;   

DOI  :  10.21577/0100-4042.20170152

学科分类：化学（综合）

来源: Sociedade Brasileira de Quimica

【 摘 要 】

The influence of the kind of metal precursor and the sequence of impregnation on the properties of Pd-Ni catalysts was evaluated during the test reaction of selective hydrogenation of styrene to ethylbenzene by means of physicochemical characterization. The focus was put on the final hydrogenating activity and the resistance to deactivation by sulfided compounds (thiophene). The used techniques of characterization were ICP, XPS, XDR, TPR, CO chemisorption and TEM. XPS results indicated the presence of different Pd species: Pdδ-, Pdº and Pdδ+. In the case of the Ni containing catalysts, Niº and NiO species were also detected. These palladium and nickel species would be responsables of the variation of activity and sulfurresistance of the catalysts. NiClPd catalysts had a higher resistance to deactivation by sulfur poisoning. This was associated to a higher concentration of Pdη+ClxOy species that would prevent the adsorption of thiophene by both steric and electronic effects. It could also be due to the lower concentration of Pdº and Niº on these catalysts, as compared to those shown by the PdNiCl catalysts. Both the Pdº and Niº species are more prone to poisoning because of their higher electronic availability.

【 授权许可】

CC BY