Effects of Intrinsic Defects in Pt-Based Carbon Supports on Alkaline Hydrogen Evolution Reaction

Abstract

Carbon material has widely been utilized in the synthesis of efficient carbon-supported Pt (Pt/C) catalysts, in which the structural properties greatly influence the electrocatalytic performances of Pt/C catalysts. However, the effects of intrinsic defects in carbon supports on the performance of the alkaline hydrogen evolution reaction (HER) have not been systematically investigated. Herein, porous carbon supports with different degrees of intrinsic defects were prepared by a simple template-assisted strategy, and the resulting samples were systematically studied by various analytical methods. The results suggested that the presence of abundant intrinsic defects (vacancy and topological defects) in the carbon support was advantageous in terms of favoring the dispersion and anchoring of Pt species, promoting electron transfer between Pt atoms and the carbon support, and tuning the electronic states of Pt species. These features improved the HER performance of Pt/C catalysts. Compared to the nontemplate-assisted carbon-supported Pt catalyst (Pt/NTC) with an overpotential of 178 mV, the optimized template-assisted carbon-supported Pt catalyst (Pt/TC) exhibited a lower overpotential of 58 mV at 10 mA cm −2 . Besides, the Pt/TC catalyst displayed better HER durability than the Pt/NTC catalyst owing to its strong metal−support interaction. The DFT calculations confirmed the important role played by intrinsic defects (vacancy and topological defects) in stabilizing Pt atoms, with Pt−C3 coordination identified as the most favorable structure for improving the HER performance of Pt. Overall, novel insights on the significant contribution of intrinsic defects in porous carbon supports on the HER performances of Pt/ C catalysts were provided, useful for future design and fabrication of advanced carbon-supported catalysts or other carbon-based electrode materials.

Hollow and Ultrathin Mo-Doped CoP Bamboo-Leaf Nanoarrays for pH-Universal Hydrogen Evolution

“…Nowadays, the widespread use of fossil energy not only occasions nonrenewable energy shortage but also leads to serious environmental pollution and unsustainable economic development. − In the cause of facilitating the continuable progress of the global economy, it is exigent to exploit reproducible clean energy and substitute fossil energy. − Hydrogen is deemed to be a desired replacement due to its environmental friendliness and high energy density. , Noble metal-based electrocatalysts appear to have outstanding activity to produce hydrogen for the HER, but their low reserve and high cost prevent actual application. − Consequently, it is still imperative to utilize nonprecious metal hydrogen evolution substances with ample sources, low price, supernal activity, and stability. , In recent years, transition metal-based materials are being widely explored, such as sulfides, , nitrides, , oxides, − and phosphides, , as preponderant HER electrocatalysts, thanks to their advantages of economical efficiency and environmental protection. Among them, transition metal phosphides (TMPs) have attracted much attention because of their low Gibbs adsorption energy. , In particular, cobalt-based phosphides possess obvious catalytic activity and durability. , In order to further improve the electrocatalytic activity, rational metal doping has been demonstrated to be a practical method. , Dopant atom substitution is finely acknowledged as an efficient tactic to ameliorate catalytic properties on account of the fact that the foreign atom can optimize the electronic structure of catalysts and the adsorption energy of intermediates. − As a common n-type dopant, Mo has the peculiarity of a large atomic radius and strong electronegativity compared with Co.…”