Synergistic CoN-Decorated Pt Catalyst on Two-Dimensional Porous Co–N-Doped Carbon Nanosheet for Enhanced Oxygen Reduction Activity and Durability

Abstract

Herein, an oxygen reduction reaction (ORR) catalyst consisting of CoN-decorated Pt nanoparticles (NPs) on thin two-dimensional (2D) nanosheet-structured Co–N-doped porous carbon is prepared by utilizing the pyrolyzed nanosheet-shaped Co-based metal–organic framework as a template for Pt deposition. After Pt deposition and acid leaching, the remaining Co species on the Pt surface are converted to CoN species by ammonia heat treatment, which are also attached on the Pt surface. The as-synthesized CoN-decorated Pt on the Co–N-functionalized 2D carbon (CoN–Pt/CoNC-2D) displays an excellent ORR activity, better than a commercial Pt/C in half-cell and single-cell tests, and also exhibits remarkable long-term durability with only a ∼17 mV shift in half-wave potential after 30 000 potential cycles. Such excellent ORR catalytic performance is attributed to strong cooperative synergistic interactions between the CoN–Pt and CoNC-2D in the catalyst. The CoN species formed on the Pt surface not only change the Pt electronic structure by down-shifting the Pt d-band center but also passivate the Pt surface to prevent Pt oxidation and dissolution during the ORR. On the other hand, the thin porous CoNC-2D nanoflake support significantly improves the accessibility of reactants to enhance mass transfer and prevents segregation and agglomeration of CoN–Pt NPs during the ORR through strong metal–support interaction, further enhancing ORR activity and durability of the CoN–Pt/CoNC-2D catalyst.

Controlled synthesis of trimetallic nitrogen-incorporated CoNiFe layered double hydroxide electrocatalysts for boosting the oxygen evolution reaction

“…XPS of monometallic catalysts (N-Co, N-Ni, and N-Fe) were also performed to determine the relationship between structural features. 5b presents the high-resolution XPS spectrum of N 1s, showing the formation of four peaks centered at 397.8 eV for cyanide CN, 37 398.5 eV for pyridinic N, 399.0 eV for metal-nitrogen (M-N x ) bonding, and 400.0 eV for pyrrolic N. 38,39 The presence of M-N x species with a peak area of 34.6% indicates the bonding between the metal atoms and amino group via a coordination interaction. The O 1s peak of N-CoNiFe, located at approximately 530.9 eV was tted to metal-oxygen (M-O x ) bonding, C-O-C, and C]O/M-OH 40 (Fig.…”

Homogeneous Distribution of Pt16(C4O4SH5)26 Clusters in ZIF-67 for Efficient Hydrogen Generation and Oxygen Reduction

“…Previous studies indicated that Co NPs and Co-N x -C sites can significantly improve the ORR activity of Pt-based catalysts (see details in the Supporting Information). − Therefore, the high ORR activity of Pt/Co@NC is attributed to the synergistic effects of Co nanoparticles, Pt NCs, and defective graphitic carbon matrix, which can offer abundant active sites and high electrical conductivity.…”

Preparation and Electrochemical Performance of a Graphene Cathode Catalyst Decorated With Pt by Prolysis

“…Ru-based compounds are the most extensively studied cathode catalytic materials among transition metal chalcogenides, however, as a precious metal, Ru is not only scarce but expensive. In addition, Co-based transition metal chalcogenides are considered to be a potential material, unfortunately, it is difficult to meet requirements imposed on both high activity and good stability under the working conditions of a PEMFC (Tran et al, 2020;Zhong et al, 2020). Although non-metallic heteroatoms doped with carbon catalysts have certain advantages in terms of cost and performance, they fail to meet the requirements for commercialization (Yang et al, 2013).…”