Synthesis of Pt/C Nanocatalysts by Galvanic Replacement for Dehydrogenation of Decalin

In this study, highly dispersed Pt/C nanocatalysts, Pt-GR/C_x (where x = 1.0, 1.5, and 2.0 wt% Pt), were synthesized via the galvanic replacement (GR) reaction between Pt ions and Cu nanoparticles (NPs) deposited on a carbon support. Using this method, Pt NPs could be supported onto activated carbon under mild conditions in an aqueous solution and without the use of any surfactant. Notably, modifying the conditions of the replacement reaction allowed control over the degree of Pt dispersion and the resulting active surface area. The prepared catalysts were characterized by transmission electron microscopy (TEM), X-ray powder diffraction (XRD), inductively coupled plasma atomic emission spectroscopy (ICP-AES), X-ray photoelectron spectroscopy (XPS), and CO-chemisorption analyses. Subsequently, they were applied to the production of H-2 via catalytic dehydrogenation of decalin and the relationship between their physical properties and catalytic activity was elucidated. The amount of the Pt ion used in galvanic replacement was kept low, which resulted in the formation of Pt NPs of size 2.04 nm that showed higher catalytic performance owing to an increased surface area. This investigation on the characterization and activity of nanocatalysts revealed that the galvanic replacement process endows noble metal catalysts with economic feasibility by less use of costly noble metal while maintaining the catalytic performance.