Novel embedded Pd@CeO2 catalysts: a way to active and stable catalysts

1-wt% Pd-CeO2 catalysts were prepared by co-precipitation of Pd nanoparticles with ceria (Pd@CeO2-CP), by a microemulsion procedure (Pd@CeO2-ME), and by normal impregnation of Pd salts (Pd/CeO2-IMP) in order to test the concept that Pd-CeO2 catalysts could be more stable for the water-gas-shift (WGS) reaction when the Pd is embedded in CeO2. Initial WGS rates measured at 250 degrees C were similar for the Pd@CeO2-CP and Pd/CeO2-IMP, indicating that Pd was accessible for gas-phase reactions on both catalysts. Pd@CeO2-CP exhibited better stability for WGS than did Pd/CeO2-IMP but exposure to the WGS environment at 400 degrees C still caused a decrease in activity. Physical characterization of the Pd@CeO2-ME implied that the core-shell nanoparticles underwent condensation that resulted in a low surface area and poor Pd accessibility. However, the Pd@CeO2-ME sample exhibited good stability for WGS, suggesting that more effective encapsulation of Pd can limit the sintering of the metal phase, thus resulting in stable catalysts under high temperature reaction conditions

Catalysts design for reforming of oxygenates

This first book to focus on the topic serves as a basis for defining a roadmap for the role of catalysis in energy production. As such, this ready reference for researchers and engineers covers all the hot topics from a broad perspective -- fuel cells, hydrogen production and storage, methane storage and industrial catalysis. With its analysis of new directions and opportunities in the area and its integration of industrial, governmental and academic points of view, this is a real must-have for everyone interested in "greener" energy production

Future perspectives for hydrogen as fuel in transportation

As energy demands continue to surge worldwide, the need for efficient and environmentally neutral energy production becomes increasingly apparent. In its first edition, this book presented a well-rounded perspective on the development of bio-based feedstocks, biodegradable plastics, hydrogen energy, fuel cells, and other aspects related to renewable resources and sustainable energy production. The new second edition builds upon this foundation to explore new trends and technologies. The authors pay particular attention to hydrogen-based and fuel cell-based technologies and provide real-world case studies of renewable energy projects in the emerging Asian and South American markets

Catalysts Design for Hydrogen Production: Embedded Rhodium Nanoparticles

Catalysts Design for Hydrogen Production: Embedded Rhodium Nanoparticle

NixCuy/Al2O3 based catalysts for hydrogen production

Ni(x wt.%) Cu(y wt.%)/Al2O3 samples were investigated as active and thermally stable catalysts for methanol and ethanol steam reforming. XRD data clearly evidenced the formation of a NiCu alloy under the adopted preparation procedure. The bimetallic systems exhibited improved activity in the methanol steam reforming with respect to the monometallic ones. The introduction of copper in the catalyst formulation showed a positive effect inhibiting the formation of methane, an undesirable by-product. On the other hand, in the ethanol steam reforming, the catalytic performance was less promising. Furthermore, the Ni : Cu ratio did not seem to affect the product distribution. However, enhanced stability was observed in the two subsequent run-up experiments, indicating the positive role played by the bimetallic systems

Stabilized metal nanoparticles embedded into porous oxides: a challenging approach for robust catalysts

Stabilized metal nanoparticles embedded into porous oxides: a challenging approach for robust catalyst

Design of [email protected] nanocomposite for ethanol steam reforming

Rh(1 wt.%)@Ce0.2Zr0.8O2(10 wt.%)-Al2O3 nanocomposite has been investigated as active and thermally stable catalyst for ethanol steam reforming. Rh nanoparticles were synthesised by surfactant assisted route, using N-hexadecyl-N-(2-hydroxyethyl)-N,N-dimethyl ammonium bromide (HEAC16Br). Metal particles with average diameter of 2.1 nm were obtained at 0.53 Rh/HEAC16Br molar ratio, while increasing the amount of surfactant lead to formation of larger particles. The preformed Rh nanoparticles have been effectively embedded into a porous layer of nanocomposite oxides. Low temperature H2 chemisorption experiments and activity data confirm that most of the Rh atoms are accessible to the reaction mixture. The Ce0.2Zr0.8O2 mixed oxide inhibits the dehydration of ethanol to ethylene and favours the water gas shift reaction. The alumina ensures good thermal stability and high surface area of the catalyst. No significant deactivation is observed after repeated run-up and run-down experiment