No abstract

A palladium nanoparticle/multiwalled carbon nanotube composite (Pd/MWCNT) was produced, characterized, and tested for catalytic activity in a hydrogen evolution reaction. The characterization included transmission electron microscopy (TEM), which confirmed the presence of the nanoparticles on the walls of the MWCNTs, scanning electron microscopy (SEM), and SEM–energy dispersive spectroscopy (EDS). TEM characterization showed the 20–35 nm diameter of the MWCNTs and the 2–4 nm diameter of the palladium nanoparticles. The composite outperformed the precursor MWCNTs and Pd nanoparticles and performed best at pH 7 at 295 K with 835 μmoles producing hydrogen at a rate of 23.0 mLmin–1gcat –1. Variation of the temperature of the reaction allowed the calculation of the activation energy, which is 62.66 kJ/mol, showing its promise as a heterogeneous catalyst for hydrogen evolution reactions.

In this study, the in-situ functionalization of gold nanoparticles onto carbon nanotubes was compared. The gold nanoparticle multi-walled carbon nanotube composites (AuMWCNT) were pretreated by two methods, one using sonication and the other incipient wetness impregnation (IWI). The produced composites were characterized using Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), and Energy Dispersive Spectroscopy (SEM-EDS). Catalytic activity of the composites with hydrogen feedstock materials was also tested, finding the stirred pretreatment most effective evolving hydrogen gas at a rate of 0.333 L mol−1 min−1.