Synergistic Hybrid Electrocatalysts of Platinum Alloy and Single-Atom Platinum for an Efficient and Durable Oxygen Reduction Reaction

Abstract

Pt single-atom materials possess an ideal atom economy but suffer from limited intrinsic activity and side reaction of producing H2O2 in catalyzing the oxygen reduction reaction (ORR); platinum alloys have higher intrinsic activity but weak stability. Here, we demonstrate that anchoring platinum alloys on single-atom Pt-decorated carbon (Pt-SAC) surmounts their inherent deficiencies, thereby enabling a complete four-electron ORR pathway catalysis with high efficiency and durability. Pt3Co@Pt-SAC demonstrates an exceptional mass and specific activities 1 order of magnitude higher than those of commercial Pt/C. They are durable throughout 50000 cycles, showing only a 10 mV decay in half-wave potential. An in situ Raman analysis and theoretical calculations reveal that Pt3Co core nanocrystals modulate electron structures of the adjacent Pt single atoms to facilitate the intermediate absorption for fast kinetics. The superior durability is attributed to the shielding effect of the Pt-SAC coating, which significantly mitigates the dissolution of Pt3Co cores. The hybridizing strategy might promote the development of highly active and durable ORR catalysts.

Ensemble Effect of Ruthenium Single-Atom and Nanoparticle Catalysts for Efficient Hydrogen Evolution in Neutral Media

“…Generally, synergic catalysis of multiple active sites can significantly lower the kinetic barriers for a multistep reaction to accelerate the reaction process . Consequently, coupling multifunctional active sites into one catalyst for complex multistep reactions is an effective strategy to improve the performance of the catalyst. − Recently, the coexistence of nanoparticles and single-atom sites, a common phenomenon during synthesis, has been demonstrated to achieve better electrocatalytic activity than separate nanoparticles and separate single atoms. − For example, Chong et al proposed that close proximity between platinum–cobalt core–shell nanoparticles and single-atom Co sites could promote the synergistic catalysis of oxygen reduction reaction (ORR) . Zhang et al designed a supported Rh catalyst with both isolated Rh atoms and Rh ensemble sites for cyclohexanol dehydrogenation, in which isolated Rh species is extremely active for the first step of dehydrogenation, and Rh ensemble sites are mainly responsible for the successive reaction step .…”

Materials for electrocatalysts in proton exchange membrane fuel cell: A brief review

“…Significant progress has been made globally towards improving the-state-of-the-art electrocatalysts for ORR. As a result of these research efforts, commercial Pt/C remains the most widely used electrocatalyst among others because of its comprehensive evaluation and the superior activity of the Pt surface to other oxygen reducing surfaces (Ma et al, 2020a;Liu et al, 2022;Li et al, 2023). However, Pt high cost, scarcity and poor durability during prolong PEMFC operation hinder the widespread commercialisation of PEMFC, as the frequent cost of the replacement of the electrocatalyst significantly affects the overall cost of the fuel cell (Lv et al, 2019b;Meng et al, 2021;Xia, 2021).…”

Probing the Roles of Indium Oxides on Copper Catalysts for Enhanced Selectivity during CO2-to-CO Electrochemical Reduction

“…Moreover, by comparing the spectra of Cu/C and Cu–In 2 O 3 /C, it is clear that the Cu oxidation is inhabited due to the surface In 2 O 3 (see more results of control samples in Figure S5 and Table S2). In Table , the Cu 0 /Cu 2+ ratio increases from 29/71 to 42/58 as long as a trace amount of In 2 O 3 is added on the Cu surface, reflecting the shielding effect of In 2 O 3 to prevent Cu oxidation …”

“…In Table 1, the Cu 0 /Cu 2+ ratio increases from 29/71 to 42/58 as long as a trace amount of In 2 O 3 is added on the Cu surface, reflecting the shielding effect of In 2 O 3 to prevent Cu oxidation. 12 The electrocatalytic CO 2 RR performance of the Cu−In 2 O 3 / C catalyst was evaluated on our customized electrochemical setup coupled with gas chromatography (GC), and the counterparts Cu/C and In 2 O 3 /C were also tested for comparison. Figure S6a depicts their linear sweep voltammetry (LSV) curves where the broad cathodic peaks of the catalysts containing In 2 O 3 are attributed to the reduction of surface In 2 O 3 .…”