RESUMEN
Metal clusters, due to their small dimensions, contain a high proportion of surface atoms, thus possessing a significantly improved catalytic activity compared with their bulk counterparts and nanoparticles. Defective and modified carbon supports are effective in stabilizing metal clusters, however, the synthesis of isolated metal clusters still requires multiple steps and harsh conditions. Herein, we develop a C60 fullerene-driven spontaneous metal deposition process, where C60 serves as both a reductant and an anchor, to achieve uniform metal (Rh, Ir, Pt, Pd, Au and Ru) clusters without the need for any defects or functional groups on C60. Density functional theory calculations reveal that C60 possesses multiple strong metal adsorption sites, which favors stable and uniform deposition of metal atoms. In addition, owing to the electron-withdrawing properties of C60, the electronic structures of metal clusters are effectively regulated, not only optimizing the adsorption behavior of reaction intermediates but also accelerating the kinetics of hydrogen evolution reaction. The synthesized Ru/C60-300 exhibits remarkable performance for hydrogen evolution in an alkaline condition. This study demonstrates a facile and efficient method for synthesizing effective fullerene-supported metal cluster catalysts without any pretreatment and additional reducing agent.
RESUMEN
The electrocatalytic hydrogen evolution reaction (HER) is one of the most studied and promising processes for hydrogen fuel generation. Single-atom catalysts have been shown to exhibit ultra-high HER catalytic activity, but the harsh preparation conditions and the low single-atom loading hinder their practical applications. Furthermore, promoting hydrogen evolution reaction kinetics, especially in alkaline electrolytes, remains as an important challenge. Herein, Pt/C60 catalysts with high-loading, high-dispersion single-atomic platinum anchored on C60 are achieved through a room-temperature synthetic strategy. Pt/C60-2 exhibits high HER catalytic performance with a low overpotential (η10) of 25 mV at 10 mA cm-2. Density functional theory calculations reveal that the Pt-C60 polymeric structures in Pt/C60-2 favors water adsorption, and the shell-like charge redistribution around the Pt-bonding region induced by the curved surfaces of two adjacent C60 facilitates the desorption of hydrogen, thus favoring fast reaction kinetics for hydrogen evolution.
RESUMEN
Carbon-based materials with superior electrochemical performances have been prepared from fullerenes by releasing their intrinsic advantages such as pentagon defects and π-electron carbons. To the best of our knowledge, fullerene-derived carbon nanotubes (CNTs) and their electrochemical behavior have not been experimentally investigated. In this work, in situ growth of CNT composites from fullerene is realized via a self-catalyzed process by employing an Fe-decorated fullerene (ferrocenylpyrrolidine C60) as the precursor and NH3 as the pyrolysis atmosphere. The results show that the in situ Fe doping in fullerene, the self-assembly of fullerene molecules, the pyrolysis temperature, and the NH3 flow play essential roles in the generation of CNTs. The as-prepared MN7-10/3 CNT composite exhibits efficient oxygen reduction performance with E1/2 = 0.82 V and Eon = 1.02 V vs the RHE. The flexible solid-state Zn-air battery constructed based on MN7-10/3 exhibits a superior power density (109.3 mW cm-2 at 180.9 mA cm-2) and long-term durability (the voltage remains at 95.6% of the initial value after discharging for 5000 s) compared with the benchmark Pt/C catalyst. The transformation of the Fe-decorated fullerene to CNTs reveals a new function of fullerenes and demonstrates a new solid-state synthetic method for CNTs.