The catalytic transfer hydrogenation on Ni electroless alloys

The catalytic transfer hydrogenation (CTH) was investigated on Ni electroless alloys, using H2PO2− ion as the H-donor and 3-buten-1-ol as a model organic compound. Ni electroless alloys films containing 7, 9 and 14 at.% of P were prepared and characterized by SEM, EDS and XRD. Cyclic voltammetry allowed to evaluate qualitatively the catalyst ability to co-adsorb the H-donor and the organic compound and revealed that the adsorption ability of 3-buten-1-ol is stronger on the highest P content alloy film. The CTH performance was characterized in terms of yield, H-donor efficiency and selectivity and the results were compared to those for the electrocatalytic hydrogenation. The dependence of the catalyst activity on the P content of the Ni alloy was found to follow different trends on the two hydrogenation methodologies. This behaviour was qualitatively explained on the basis of the competitive adsorption of 3-buten-1-ol and the supplier of hydrogen. It was concluded that hydrogenation of a strong adsorbable unsaturated organic compounds is more successful through the use of an H-donor than through the electrocatalytic hydrogenation.In the course of the CTH run, the Ni alloy deactivation was observed, but re-activation of the catalyst by applying a rather negative potential was attained. Dependence of the time lag for deactivation with the P content of the Ni alloy was found. The source of the deactivation was investigated and an explanation for this phenomenon was proposed.

A comprehensive investigation on the catalytic transfer hydrogenation, using the hypophosphite ion as the hydrogen donor and 3-buten-1-ol as a model molecule, was carried out on Ni–P electroless films containing 7–14 at.% of P. The performance of the hydrogenation, in terms of the reaction yield, selectivity and H-donor efficiency were found to depend on the P content of the Ni alloy. In the course of the CTH run, the Ni alloy deactivation was observed. The source of the deactivation was investigated and an explanation for this phenomenon was proposed.Figure optionsDownload as PowerPoint slide