Highly active heteropolyanions supported Co catalysts for fast hydrogen generation in NaBH4 hydrolysis

This paper reports on the use of Co supported catalyst for the hydrolysis of NaBH4. Various materials with different acid/base surface properties have been chosen as supports (hydrotalcites, KF/Al2O3, heteropolyanions). The supports and the Co-containing catalysts were characterized by X-ray diffraction, scanning electron microscopy with energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, inductively coupled plasma, nitrogen adsorption. The NaBH4 hydrolysis reaction was studied in a liquid phase calorimeter coupled with a gas counter in order to follow at the same time the kinetics and the heat of reaction. Co supported on heteropolyanions showed great results in terms of reaction rate. Cobalt dispersed on heteropolyanions is a real promising catalytic system for the development of hydrogen generation in PEM fuel cells for portable devices.

Graphical abstractHydrogen generation from NaBH4 hydrolysis in the presence of heteropolyanions supported Co catalysts .Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► The protonic acidity of the HPA support plays a key role in the improved activity of the Co-based systems, even if it cannot be responsible alone of their high activity. ► The bifunctional combination of both acidic and metallic properties acts as a synergetic effect, thus enhancing the bonding role of the support. ► The Co-based samples prepared on highly acid heteropolyanionic supports show much higher catalytic performances than those prepared on basic supports.