Effect of reducing gas on the hydrogen production by thermo-oxidation of water over 1%Rh/Ce 0.6 Zr 0.4 O 2
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Effect of reducing gas on the hydrogen production by thermo‑oxidation of water over 1%Rh/Ce0.6Zr0.4O2 B. Benaziza1 · A. Benamar1 · N. Helaili2 · M. Zaghrioui3 · M. Anouti3 · M. Trari2 Received: 26 December 2019 / Accepted: 3 October 2020 © Springer Nature B.V. 2020
Abstract We have studied the effect of the reducing gas (H2, CO and CH4) on the hydrogen production by thermo-oxidation of water over the 1%Rh/Ce0.6Zr0.4O2 catalyst prepared by impregnation. The catalyst is characterized by hydrogen chemisorption (Hc), before and after catalytic decomposition of water, temperature-programmed desorption, temperature-programmed reduction, X-ray diffraction and scanning electron microscopy. The catalyst is reduced in situ at 500 °C (4 h) under H 2, CO or CH4 flows and flushed with Ar gas. Then, pulses of water (1 μL/pulse) are injected at 500 °C under Ar flow (30 mL/min). The results show clearly that the reducing gas has a strong effect on the H2 production which follows the order: H2 > CH4 > > CO. H2 chemisorption measurements at room temperature highlight a strong metal–support interaction over fresh reduced catalysts which decreases after water decomposition (reduced centers + H2O → oxidized centers + H2). Keywords Hydrogen formation · Rhodium · Cerium–zirconium oxide · Hydrogen · Catalysts
Introduction The gradual disappearance of the fossil energy resources and the environmental problems like the global warming have forced the scientists to turn to the renewable and clean sources of energy. Therefore, the energetic sources and their accessibility are among the main challenges in the future [1]. In this respect, many new * M. Trari [email protected]; [email protected] 1
Laboratory of Materials and Application to the Environment, Faculty of Chemistry, USTHB, BP 32, 16111 Algiers, Algeria
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Laboratory of Storage and Valorization of Renewable Energies, Faculty of Chemistry, USTHB, BP 32, 16111 Algiers, Algeria
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Université François-Rabelais de Tours, GREMAN UMR 7347 CNRS, IUT de Blois 15 rue de la chocolaterie CS 2903, 41029 Blois Cedex, France
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technological developments are associated with energy, namely the hydrogen which is considered as a potential energy carrier; it is the less harmful forms for the environment. Equipped with cycle closed energy, it contributes to various applications, such as electricity generation and fuel for transportation [2–9]. To overcome and solve the problems associated with the fossil fuels combustion, many researches on hydrogen formation from water splitting were already published. In this regard, the thermochemical cycles [10–12] and photocatalysis using solar energy are attractive because they display less energy [13, 14]. However, some authors have studied the reduction of silica and alumina-supporting Rh or Pt catalysts at 500 °C, and this also leads to the reduction of the perimeter surface, thus generating oxygen vacancies due to interactions with noble metals [15]. So, it is clear that strong metal–support inte
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