Investigation of active metal species formation in Pd-promoted sulfated zirconia isomerization catalyst

FTIR Spectroscopy of Adsorbed Probe Molecules for Analyzing the Surface Properties of Supported Pt (Pd) Catalysts

“…Supposedly, the formation of metallic palladium can be caused by evacuation at high temperatures during the pretreatment in IR cell. This assumption was confirmed in a special experiment by means of UV-vis spectroscopy (Belskaya et al, 2010). Pd/SZ catalyst after the oxidation is characterized by a.b.…”

“…Thus, in Pd/SZ catalysts, after the reduction treatment at 300 °C, hydrogenation activity of palladium is strongly inhibited. However, the constant activation energy and complete recovery of hydrogenation activity under mild regeneration conditions (Belskaya et al, 2010) indicate that the metal surface is only blocked by sulfate decomposition products without their chemical interaction with palladium.…”

“…at 2135 and 2160 cm −1 are observed in the spectra of CO adsorbed on Pd/SZ samples that were reduced at 300-350 °C. These bands appear on admission of 0.1 mbar CO and grow in intensity with increasing CO pressure (Belskaya et al, 2010); they are attributed to CO complexes with oxidized Pd + and Pd 2+ species, probably in Pd n+ -S 2-sites (Vazquez-Zavala et al, 1994). Fig.…”

“…In our earlier work (Belskaya et al, 2010), this method was used for studying the state of supported palladium particles in Pd/SZ under different conditions of catalyst pretreatment. In the experiment, the catalyst treatment in various gas media (air, hydrogen) and at different temperatures (100-400 °C) was performed directly in a spectrometer cell.…”

Investigation of Palladium Catalysts in n-hexane Isomerization Reaction

“…Much attention is paid to catalysts on the basis of sulfate dioxide of zirconium which combine high activity, poisons resistance and work in thermodynamic favorable interval of temperatures 140-180 ºС. Traditionally, platinum is used as an active component in catalysts of isomerization of alkanes, however palladic catalysts also possess high isomerizating ability [1,2]. At the moment palladic the sulphate zirconia of catalysts is paid much less attention to research in literature than to studying platinum systems on the basis of SO 4 2 -/ZrO 2 .…”