Sandwich-Structured MXene/Carbon Hybrid Support Decorated with Pt Nanoparticles for Oxygen Reduction Reaction

Abstract

Carbon supports for cathodic catalysts in proton-exchange membrane fuel cells suffer from rapid corrosion and instability; therefore, alternative supports with a stable structure and a high electric conductivity are highly required. In this paper, a three-dimensional support hybridized by MXene and Ketjen Black is developed, in which Ketjen Black is sandwiched between MXene nanosheets (MCM). After decorating with Pt nanoparticles by a facile wet-chemical approach, a three-dimensional (3D) Pt/MCM catalyst is obtained. The intercalated Ketjen Black prevents the stacking of MXene nanosheets, thus increasing the specific surface area of the catalyst and exposing the active sites. The strong interaction between functionalized MXene nanosheets and Pt nanoparticles further enhances its intrinsic electrocatalytic activity. Pt/MCM demonstrated encouraging ORR activity with the half-wave potential and specific activity of 0.892 V and 0.377 mA·cm–2, respectively, surpassing the state-of-the-art Pt/C catalysts. Especially, Pt/MCM achieves ultrahigh durability with a 1 mV decrease in half-wave potential and a 1.73% decrease in mass activity after an accelerated durability test. Given the performance and structure–activity relationships of Pt/MCM, it holds great potential for various energy and catalysis-related applications.

Exposing an Environmentally Friendly Gelation Strategy to Fabricate Modern Three-Dimensional M–Ag (M = Pt and Pd) Aerogels with Excellent Green Energy Generation

“…These high activities are due to the interaction of all electrocatalysts with the clean available active sites. However, the cleavage of CH 3 CH 2 OH molecules leads not only to the generation and adsorption of intermediate species on the aerogel surface but also to a sharp decrease in the specific activity owing to the poisoning and blocking of the active sites. − The steeper slope of the CA profile for Pt–Ag aerogel suggests a greater poisoning and less stability against Pd–Ag aerogel. Additionally, the gradual decrease in CA plots for both engineered aerogels relative to the Pd/C catalyst highlights their incredible electrocatalytic durability.…”

Bimetallic Pd–Co Aerogel Three-Dimensional Architecture: Developing Self-Assembled Materials for Advanced Ethanol Oxidation

“…EIS (electrochemical impedance spectroscopy) analysis was conducted to study the charge transfer resistance ( R CT ) at the surface of Pd 92 Co 8 aerogel. − This analysis for both compounds was conducted at 298 K in a K­[Fe­(CN) 6 ] 3–/4– environment and the achieved plots are represented in Figure S5. In comparison with Pd/C, a boosted conductivity is expected for Pd 92 Co 8 aerogel since the assembled 3D superstructure reflects a lower R CT (230 vs 354 Ω).…”

“…The energy crises worldwide and the problems caused by fossil fuels have intensified the requirement of modern society for renewable energy. Hence, at the beginning of the present century, electrocatalysis-related processes have emerged as hot research topics to develop sustainable energies such as direct fuel cells (DFCs), water splitting, oxygen reduction reaction (ORR), batteries, supercapacitors, and so forth. − Among them, DFCs have received much attention as a young technology to supply the required energy in various industries. However, the problems caused by the insufficient efficiency and unfavorable stability of catalysts have created grand challenges in electrocatalysis processes.…”