Reactions involved in the electrodeposition of hydrotalcite-type compounds on FeCrAlloy foams and plates

Electrochemical Approach for the Production of Layered Double Hydroxides with a Well-Defined Co/MeIII Ratio

Layered double hydroxides (LDHs) have been widely studied for their plethora of fascinating features and applications. The potentiostatic electrodeposition of LDHs has been extensively applied in the literature as a fast and direct method to substitute classical chemical routes. However, the electrochemical approach does not usually allow for a fine control of the M^II /M^III ratio in the synthesized material. By employing a recently proposed potentiodynamic method, LDH films of controlled composition are herein prepared with good reproducibility, using different ratios of the trivalent (Fe or Al) to bivalent (Co) cations in the electrolytic solution. All the obtained materials are shown to be effective oxygen evolution reaction (OER) catalysts, and are thoroughly characterized by a multi-technique approach, including FE-SEM, XRD, Raman, AES and a wide range of electrochemical procedures.

Insights into coated NiCrAl open-cell foams for the catalytic partial oxidation of CH4

NiCrAl foams coated by a catalytic layer are stable under reaction conditions and decrease the hot spots, making them an alternative to FeCrAl materials.

Hydrotalcite-Type Materials Electrodeposited on Open-Cell Metallic Foams as Structured Catalysts

Structured catalysts based on hydrotalcite-derived coatings on open-cell metallic foams combine tailored basic/acidic sites, relatively high specific surface area and/or metal dispersion of the coating as well as low pressure drop and enhanced heat and mass transfer of the 3D metallic support. The properties of the resulting structured catalysts depend on the coating procedure. We have proposed the electro-base generation method for in situ and fast precipitation of Ni/Al and Rh/Mg/Al hydrotalcite-type materials on FeCrAlloy foams, which after calcination at high temperature give rise to structured catalysts for syngas (CO + H2) production through Steam Reforming and Catalytic Partial Oxidation of CH4. The fundamental understanding of the electrochemical-chemical reactions relevant for the electrodeposition and the influence of electrosynthesis parameters on the properties of the as-deposited coatings as well the resulting structured catalysts and, hence, on their catalytic performance, were summarized.