Ceria supported copper(0) nanoparticles as efficient and cost-effective catalyst for the dehydrogenation of dimethylamine borane

Abstract

This work aims the preparation and catalytic use of copper(0) nanoparticles supported on ceria as catalyst in dehydrogenation of dimethylamine borane. They were in situ generated from the reduction of Cu2+/CeO2 during the catalytic dehydrogenation of dimethylamine borane in toluene. The results of characterization by using XRD, SEM, SEM-EDX, TEM, UV–vis, XPS techniques reveal the formation of highly dispersed copper(0) nanoparticles with average particle size of 3.1±0.8nm on the surface of ceria nanopowders. Cu(0)/CeO2 nanoparticles are active catalysts releasing 1.0equiv. H2 per mole of dimethylamine borane. The catalytic activity of Cu(0)/CeO2 shows variation with the copper loading of ceria and the highest catalytic activity is achieved by using Cu(0)/CeO2 sample with a copper loading of 4.0wt.% Cu which provides a turnover frequency value of 40h−1 and 225 turnovers in hydrogen generation from dimethylamine borane at 60.0±0.5°C. The equation for the catalytic reaction was established by determining all the products. We performed the kinetic studies for understanding the catalytic dehydrogenation of dimethylamine borane in molecular level. The results of kinetic study reveal that the reaction is first order with respect to catalyst concentration. The work reported here also includes the kinetic study depending on the temperature to determine the activation energy (Ea=76±2kJ/mol).