Wojciech K. Jóźwiak

Characterization of Ru/CeO2-Al2O3 catalysts and their Performance in CO2 Methanation

Ru/Al2O3 and Ru/CeO2-Al2O3 samples were used as catalysts in CO2 methanation. The catalysts were characterized by temperature-programmed reduction (TPR) and X-ray diffraction. The promoting effect of ceria on the catałytic activity of the catalysts under study in CO2 methanation was observed.

Copper-supported catalysts in methanol synthesis and water gas shift reaction

The comparative studies of physicochemical properties of Cu-support catalysts (support = ZnO, Al2O3, Cr2O3, ZnAl2O4, FeAlO3, or CrAl3O6) and their catalytic activity in methanol synthesis and water gas shift reaction were the main goal of this work. The promotion effect of copper addition in both reaction was proved. The formation of spinel type structure CuCr2O4, ZnAl2O4 and binary oxide CrAl3O6, FeAlO3 during calcination process was confirmed by XRD technique. Results showed that 20% Cu/FeAlO3 had the best performance in water gas shift reaction. The best selective and active catalyst in methanol synthesis was 20% Cu/ZnAl2O4.

The effect of the nature of the support on catalytic properties of ruthenium supported catalysts in partial oxidation of methane to syn-gas

The effect of the carrier on catalytic properties of ruthenium supported catalysts in partial oxidation of methane (POM) was investigated. A variety of supports differed in texture and reducibility (Al2O3, SiO2, TiO2, Cr2O3, CeO2 and Fe2O3) were used. The catalyst activity is governed by ruthenium phase formation (RuO2 → Ru0), and it depends on redox properties of the support as well as support-ruthenium phase interaction. The activity of Ru supported catalysts decreases in the order Al2O3 ≈ SiO2 > Cr2O3 > TiO2 > CeO2 > Fe2O3. No significant effects of the specific surface area and porosity of catalysts on the methane conversion and selectivity of CO formation were found. The selectivity of CO2 formation (total oxidation of CH4) under conditions of POM (a ratio of CH4/O2 = 2) is associated with the contribution of reducible support oxides into the catalytic performance.

Temperature programmed desorption of hydrogen from 5 % Rh/ZrO2 catalyst

A considerable effect of the conditions of hydrogen adsorption (temperature, time) and the number of measurement cycles HT−OT on results of hydrogen TPD for Rh/ZrO2 catalyst has been observed. Deactivation of rhodium surface at room temperature, conditioned by high temperature reduction seems to be due to a strongly temperature-activated hydrogen adsorption.AbstractНаблюдали значительное влияние условий водородной адсорбции (температура, время) и числа измеряемых циклов HT−OT на результаты водородной ТПД на катализаторе Rh/ZrO2. Дезактивация родиевой поверхности при комнатной температуре, кондиционированная высокотемпературным восстановлением, вызвана сильно активированной температурой адсорбцией водорода.

The influence of addition of silver and copper on the reducibility of CrAl 3 O 6 system

The influence of addition of silver and copper on the reduction behavior of binary oxide CrAl3O6 was investigated. The formation of copper chromite CuCr2O4 and silver chromate Ag2CrO4 during calcinations process was observed. The intermediate phase CrO was detected when copper and silver-copper systems were reduced at temperatures above 500°C. This intermediate is formed from Cr2O3, which is yielded by the initial reduction of Cr2O42− species.

Thermal and thermo-catalytic degradation of polyolefins as a simple and efficient method of landfill clearing

Thermal and thermo-catalytic degradation of polyolefins as a simple and efficient method of landfill clearing Thermal degradation of the low density polyethylene (LDPE), polypropylene (PP) and the municipal waste plastics was investigated. The thermo-catalytic degradation of LDPE and PP was studied in the presence of the following catalysts: four different types of montmorillonite: K5, K10, K20, K30 and - for comparison - zeolites (natural - clinoptilolite, YNa+ and YH+). Thermal analyses TG-DTA-MS of polymers and polymer-catalyst mixtures were carried out in an argon flow atmosphere in isothermal and dynamic conditions. The following order was found: in lowering the reaction temperature for LDPE degradation YH+ > mK5 > mK20 = mK30 >mK10 > NZ > YNa+; for PP degradation: mK20 > mK5 = mK30 >mK10 > YH+ > NZ > YNa+. The activity tests were carried out in a stainless steel batch reactor under atmospheric pressure in a wide temperature range of up to 410°C, and using the atmosphere of argon flow. The liquid products were analysed by the GC-MS method. The hydrocarbons in the liquid products from thermal degradation of polymers were broadly distributed in the carbon fractions of C8 to C26 - for LDPE and C6 to C31 for PP.