Enhanced catalytic activity of monodispersed AgPd alloy nanoparticles assembled on mesoporous graphitic carbon nitride for the hydrolytic dehydrogenation of ammonia borane under sunlight
silver, palladium, alloy nanoparticles, graphitic carbon nitride, ammonia borane, dehydrogenation
ABSTRACT We address the composition-controlled synthesis of monodispersed AgPd alloy nanoparticles (NPs), their assembly for the first time on mesoporous graphitic carbon nitride (mpg-C3N4), and the unprecedented catalysis of mpg-C3N4@AgPd in the hydrolytic dehydrogenation of ammonia borane (AB) at room temperature. Monodispersed AgPd alloy NPs were synthesized using a high-temperature organic-phase surfactant-assisted protocol comprising the co-reduction of silver(I) acetate and palladium(II) acetylacetonate in the presence of oleylamine, oleic acid, and 1-octadecene. This protocol allowed the synthesis of four different compositions of AgPd alloy NPs. The AgPd alloy NPs were then assembled on mpg-C3N4, reduced graphene oxide, and Ketjenblack using a liquid-phase self-assembly method. Among the three supports tested, the mpg-C3N4@AgPd catalysts provided the best activity because of the Mott–Schottky effect, which was driven by the favorable work function difference between mpg-C3N4 and the metal NPs. Moreover, the activity of the mpg-C3N4@AgPd catalyst was further enhanced by an acetic acid treatment (AAt), and a record initial turnover frequency of 94.1 mol(hydrogen)·mol(catalyst) −1·min−1 was obtained. Furthermore, the mpg-C3N4@Ag42Pd58-AAt catalyst also showed moderate durability for the hydrolysis of AB. This study also includes a wealth of kinetic data for the mpg-C3N4@AgPd-catalyzed hydrolysis of AB.
Tsinghua University Press
Hamza Kahri,Melike Sevim,Önder Metin, Enhanced catalytic activity of monodispersed AgPd alloy nanoparticles assembled on mesoporous graphitic carbon nitride for the hydrolytic dehydrogenation of ammonia borane under sunlight. NanoRes.2017, 10(5): 1627–1640