Isotopic Study of Sodium Borohydride Reduction Mechanisms Catalyzed by Metal-Nanoparticles

Nowadays, metals are widely used in the chemical industry. In particular, noble metals are extensively employed in industry, agriculture, jewelry and in the medicinal world. A wide range of industrial catalytic reactions involve extensive usage of metals especially in solid state catalysis. Often, poisoning of metal surfaces occurs during catalytic reactions under extreme conditions results in a widespread impact on the environmental pollution.¹

One of the most studied resolutions for this environmental problem is catalysis based on nanoparticles (NPs) and in particular on metal NPs in liquid phase. NPs are known for their high catalytic efficiency in mild conditions and they are extensively investigated due to their surface to volume ratio properties.²

Reduction is among important industrial catalytic reactions. Thus, we have chosen to study reduction reactions and in particular water reduction. There are many studies engaged in catalytic water reduction by sodium borohydride but the mechanism of these reactions is still not known.

We are investigating the catalytic reduction by borohydride on metal NPs catalysts (silver, gold and platinum NPs) using sodium borodeuteride (NaBD4) as an isotopic marker. We are using GC, MS and TEM to analyze the reactions` products and the catalysts properties. The data obtained especially by the MS, will give an insight on the reduction mechanisms and the kinetics of the system investigated.

_{(1) Somorjai, G. A.; Rioux, R. M. High Technology Catalysts towards 100% Selectivity: Fabrication, Characterization and Reaction Studies. Catal. Today 2005, 100 (3–4), 201–215.}

_{(2) Zidki, T.; Cohen, H.; Meyerstein, D. Reactions of Alkyl-Radicals with Gold and Silver Nanoparticles in Aqueous
Solutions. Phys. Chem. Chem. Phys. 2006, 8 (30), 3552–3556.}