Showing papers by "Martin Schmal published in 2023"
TL;DR: In this paper , the authors presented the synthesis and performance of two different materials supports, silica and carbon, impregnated with 5% Nickel and the effect of reaction condition and feed compositions on the tri-reforming for the synthesis gas production.
Abstract: In this work we presented the synthesis and performance of two different materials supports, silica and carbon, impregnated with 5% Nickel and the effect of reaction condition and feed compositions on the tri-reforming for the synthesis gas production. The highest conversions of CH4 and CO2 were obtained at 750 °C and weight hourly space velocity (WHSV) 1250 mL/g.min. The 5%Ni/MWCNT catalysts reached 90.2% and 76.5% conversions of CH4 and CO2, while the catalyst 5%Ni/SBA-15%, 87.4% and 64.7%, respectively. The conversions for the MWCNT are significantly higher than for the SBA-15 at 750 °C, but the yields of H2 and selectivity of CO decreased on the SBA support. The influence of the feed conditions on the activity was tested. Both catalysts demonstrated high activity and good stability. TGA results after reaction showed that the carbon nanotubes were preserved, and SBA-15 is more resistant to carbon formation under such reaction conditions.
TL;DR: In this article , the authors used sol-gel and sonochemical methods to prepare bimetallic PdCu catalysts supported on modified ZrO2 with Ti and Al.
Abstract: This work uses sol–gel and sonochemical methods to prepare bimetallic PdCu catalysts supported on modified ZrO2 with Ti and Al. The catalysts are tested for vinyl acetate synthesis from ethylene, acetic acid, and oxygen, varying the reaction temperature for two catalysts prepared, which show higher activity. Catalysts characterization results show bimetallic species and distort alloys with a dispersed distribution of active metal onto the support. The in situ reaction by DRIFT-MS identifies the surface formation of main intermediates like palladium acetate monomers and mono and bidentate intermediates, associated to vinyl acetate formation, like vinyl hydrogenated species over PdCu. Finally, this behavior will be attributed to the bimetallic distortions of PdCu samples, provided by interaction effects between PdCu and supports, indicating a more exposition of PdCu species suitable for the reaction, according to high-resolution transmission microscopy electron microscopy results for PdCu/ZrTi sample. Thus, this sample exhibits a minimal formation of sub-products and catalytic stability for 18 hh. These results evidence the participation of hydroxyls and oxygen vacancies of the catalyst in the catalytic reaction measured in situ, monitoring the products formed at the reactor outlet. Finally, it is proposed a reaction pathway as a function of reaction conditions.