Filomena Castaldo

Catalytic Activity of Ceo2 Supported Pt-ni and Pt-co Catalysts in the Low Temperature Bio-ethanol Steam Reforming

Low temperature bio-ethanol steam reforming (ESR) can be considered a promising method to produce H2, owing the increase of thermal efficiency and reduction of capital costs. However, some detrimental effects such as lower H2 selectivity and catalyst deactivation can occur, making crucial the catalysts selection. The aim of this work is to study bimetallic Pt based catalysts for the low temperature ESR reaction in concentrated reaction mixture. Preliminary results concerning economic aspects are also reported.

Sustainable Hydrogen Production by Catalytic Bio-Ethanol Steam Reforming

Energy is an essential input for social development and economic growth. At present, globally the demand for energy is increasing in consonance with socio-economic development, though in developing countries it increases a little bit more quickly than developed countries. Energy consumption in developed countries grows at a rate of approximately 1% per year, and that of developing countries, 5% per year.

Time-on-stream stability of new catalysts for low-temperature steam reforming of biogas

Time-on-stream stability of six different steam reforming catalysts has been tested at 500 °C under a simulated biogas feed. The catalysts are based on different combinations of Ni, Pt and Rh as active species, and CeO₂, ZrO₂ and La₂O₃ as support. In order to perform a conservative analysis, biogas was simulated with a 50 % v/v CO2-CH4 mixture; furthermore a steam to methane ratio as low as 2.5 has also been used. All the samples containing CeO₂ in the support proved fairly stable up to 50 h on stream. Therefore, these catalysts are worth being further investigated to assess their activity and determine appropriate reaction rate expressions.

High Thermal Conductivity Structured Bimetallic Catalysts for Low Temperature Ethanol Steam Reforming

This study focuses on the development of bimetallic structured catalysts, supported on CeO2 and CeO2–ZrO2, active in Ethanol Steam Reforming (ESR) reaction at low-temperature (300–600 °C) and characterized by improved heat transfer properties. ESR reaction was carried out on ceramic foams and on powders catalysts. In particular, catalytic test were performed on two reactor configurations (annular and tubular), evidencing that the better thermal management of the foams, tested in the tubular reactor, results in very higher conversions mainly due to the overcoming heat transfer limitations. Moreover, the effect of catalytic support on system performances was investigated.

Bimetallic Catalysts for Hydrogen Generation by Low Temperature Ethanol Steam Reforming

The production of hydrogen through the low temperature-ethanol steam reforming (LT-ESR) reaction requires the development of an efficient catalyst. A bimetallic formulation, based on Pt and Ni and supported on CeO2 was investigated, in terms of activity, selectivity, stability. Very interesting results were obtained, with a complete ethanol conversion and a perfect agreement between the experimental and equilibrium products distributions, yet at T ≥ 300 °C, contact time=240 ms and stoichiometric water/ethanol molar ratio. Furthermore, the selectivity towards the desired compounds was very high, with low coke selectivity and appreciable stability, especially with higher water/ethanol ratio. A mechanistic study of the reaction was carried out through the detailed analysis of the experimental evolution of the products distribution as a function of contact time (3 – 600 ms) and temperature (340 – 480 °C). The most significant result was the formulation of a possible Pt/Ni/CeO2 catalysed reaction pathway, that includes the following steps: ethanol adsorption followed by dehydrogenation to acetaldehyde; intermediate decomposition and reforming to CH4, CO, H2 and CO2; CO-WGS and CO2 methanation reaction. These outcomes were validated by specified characterizations of the exhaust sample, as temperature programmed desorption (TPD) experiments.