The photocatalytic reduction of carbon dioxide with hydrogen was studied by Temperature-Programmed Surface Reaction (TPSR). This process was carried out in a flow reactor that was especially designed and constructed for this purpose. Titanium dioxide (TiO2, Degussa P-25) was used as supports for platinum, ruthenium and nickel catalysts. The experimental results indicated that the activity of photoreduction of CO2 changes as follows: Ru/TiO2 > Ni/TiO2 > = Pt/TiO2 > TiO2.
Time-of-flight secondary ion mass spectrometry (ToF-SIMS) was used in order to obtain the information about the surface composition of Pd/ZrO2-TiO2 catalyst and to estimate the changes in the concentration of particular components on its surface during the hydrodechlorination of CCl4. The results demonstrated that the hydrodechlorination process led to the increase in the concentration of chlorine and the drop in the amount of surface accessible palladium, while the quantity of Pd-Cl bounds did not change considerably. It suggested that the presence of ZrO2 protected the surface of the studied catalyst against the formation of PdCl2.
The aim of this paper was to investigate the physicochemical properties of palladium catalyst containing basic support MgO which was used in hydrodechlorination reaction with carbon tetrachloride. In order to characterize the investigated sample the catalyst was put to tests of XRD, TOF - SIMS, TG-DTA-MS and TPRH2 measurements, activity tests were also performed. The XRD and TPR results demonstrated the presence of PdOxCly species whose decomposition takes place above 700°C. The calcination of the Pd/MgO catalyst at 700°C resulted in the transformation of PdOxCly to PdO.
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