Pt/C catalysts containing CeO2 with different morphologies for the hydrogen evolution reaction.

Pt/C catalysts containing four different morphologies of CeO₂ as co-catalysts were synthesized in this work, and their electrocatalytic performance for hydrogen evolution reaction (HER) was investigated. As compared with the Pt/C catalyst, these four catalysts containing CeO₂ all exhibited improved catalytic activity. Among them, the Pt/C catalyst containing spherical CeO₂ with a diameter of 30 ~ 60 nm (Pt/C-CeO₂(s₂)) possesses the best catalytic activity, displaying an over-potential of 258 mV at 10 mA cm⁻² and a Tafel slope of 42 mV dec⁻¹. According to the characterization results of structure, morphology, and elemental valence state, the enhancement of catalytic activity is ascribed to the small particle size and good dispersion degree of Pt, as well as the strong interaction between the exposed (111) crystal plane of small spherical CeO₂ and Pt, which leads to a significant increase in metallic Pt content. Moreover, the Pt/C-CeO₂(s₂) catalyst also demonstrates outstanding long-term stability besides exceptional catalytic activity. The results clearly illustrate that CeO₂ with diverse shapes and sizes can remarkably influence the catalytic performance of loaded Pt particles in the HER process. [ABSTRACT FROM AUTHOR]