Giuseppe Monforte

Investigation of direct methanol fuel cells based on unsupported Pt-Ru anode catalysts with different chemical properties

The structure, chemistry and morphology of commercial unsupported Pt–RuOx and in-house prepared Pt–Ru catalysts were analysed. The catalytic activity of these materials towards electro-oxidation of methanol in solid-polymer-electrolyte direct methanol fuel cells have been investigated at 130°C. The in-house prepared unsupported Pt–Ru catalyst showed higher performance with lower activation control and mass polarisation losses in relation to the Pt–RuOx catalyst. An enhancement of mass-transport properties was obtained in the presence of interdigitated flow-fields. Maximum power densities of about 0.45 and 0.29 W cm−2 in the presence of oxygen and air-feed, respectively, were obtained at 130°C. Methanol cross-over rates and fuel efficiency were determined under various conditions.

Ageing effects of electrodes in ceramic fuel cells

Abstract A physico-chemical characterization of aged electrodes of a 150 W solid oxide fuel cell (SOFC) tubular stack is presented. X-ray diffraction and electron microscopy analyses showed that significant chemical and morphological changes occurred in both anodic and cathodic components after 3000 h operation. Depletion of ceria at the anode side with operation time caused a change in selectivity of the methane oxidation reaction, leading to a significant increase of the deep oxidation products in the catalytic step preceding the electrochemical reaction. This determined both OCV drop and performance decay. Moreover, prolonged operation resulted in a narrowing of the three-phase reaction zones at the electrode-electrolyte interface.

A Novel Anode Based on Ni-Modified Perovskite for Direct Alcohol Solid Oxide Fuel Cells

A Ni-modified La0.6Sr0.4Fe0.8Co0.2O3 / Ce0.9Gd0.1O2 catalyst was prepared by incipient wetness. The product thus obtained was calcined at 1100°C for 2 h in static air. After thermal activation, Ni was mainly present as highly dispersed La2NiO4 on the surface of perovskite surface. The thermal reduction at 800 °C caused the occurrence of metallic Ni on the surface. Surface area was determined by BET measurement. The catalyst was used as anode in IT-SOFCs fed with methanol. Studies under steam reforming, partial oxidation and autothermal reforming of methanol were carried out at 800°C. A comparison was made between the performance of SOFCs fed with syngas or methanol. The results with methanol are promising both in terms of energy density as well as suitable performance for portable power sources.

Natural pyrite-based electrodes for photoelectrochemical applications

Abstract The screen printing technique has been used for the manufacturing of photoelectrodes based on natural pyrite. Materials have been investigated by X-ray diffraction, energy dispersive X-ray analysis and scanning electron microscopy. Information on the electrochemical reactivity of the surface has been obtained by cyclic voltammetry in alkaline solution. Photoactive anodes in polyiodide electrolyte based photoelectrochemical cells have been obtained upon thermal activation of electrodes in air. These results have been interpreted on the basis of the formation of a heterostructure composed of FeS 2 and Fe 2 O 3 phases.