Rafael M. Reis

Desenvolvimento e avaliação de eletrodos de difusão gasosa (EDG) para geração de H2O2 in situ e sua aplicação na degradação do corante reativo azul 19

This work reports the development of GDE for electrogeneration of H2O2 and their application in the degradation process of Reactive Blue 19 dye. GDE produced by carbon black with 20% polytetrafluoroethylene generated up to 500 mg L-1 of H2O2 through the electrolysis of acidic medium at -0.8 V vs Ag/AgCl. Reactive Blue 19 dye was degraded most efficiently with H2O2 electrogenerated in the presence of Fe(II) ions, leading to removal of 95% of the original color and 39% of TOC at -0.8 V vs Ag/AgCl.

Nickel–Iron/Gadolinium-Doped Ceria (CGO) Composite Electrocatalyst as a Protective Layer for a Solid-Oxide Fuel Cell Anode Fed with Biofuels

The performance and reliability of a commercial solid‐oxide fuel cell (SOFC) with the anode coated by a protective catalytic layer is demonstrated. Physico‐chemical and electrochemical characterizations of a Ni–Fe/gadolinium‐doped ceria (CGO) electrocatalyst forming the protective layer are reported. The anode layer was prepared by using a procedure that favors the interaction between Ni and Fe. Power densities approaching 0.3 W cm−2 for the SOFC cell fed with dry organic fuels were obtained. A time test was performed in the presence of a large flow rate of dry organic fuels under operating conditions (0.8 V) showing appropriate fuel flexibility for the device. The resistance to sulfur contamination was verified by feeding increasing amounts of H2S. The cell showed only moderate performance losses until 80 ppm of sulfur contaminant.

Degradation of dipyrone by the electro-Fenton process in an electrochemical flow reactor with a modified gas diffusion electrode

The increasing occurrence of antibiotics and their metabolites in surface and ground waters is causing a significant impact on the environment and needing of developing novel treatments for the complete removal of such contaminants. This paper presents the study of the electrogeneration of hydrogen peroxide (H2O2) in acidic medium and the degradation of the analgesic dipyrone in an electrochemical flow reactor using a gas diffusion electrode (GDE) modified with 5.0% cobalt (II) phthalocyanine (CoPc) and pressurized with O2. The highest yield of H2O2 (133 mg L-1) was achieved after 90 min of electrolysis at an applied potential of -2.1 V (vs. Pt//Ag/AgCl/KCls) and the best results for degradation of dipyrone were obtained under electro-Fenton conditions, where the total organic carbon (TOC) was reduced 62.8% after 90 min of reaction and 49.1 kW h of energy was consumed per kg of dipyrone degraded.