Polyaniline-Functionalized Carbon Nanotube Supported Platinum Catalysts

Abstract

Electrocatalytically active platinum (Pt) nanoparticles on a carbon nanotube (CNT) with enhanced nucleation and stability have been demonstrated through introduction of electron-conducting polyaniline (PANI) to bridge the Pt nanoparticles and CNT walls with the presence of platinum-nitride (Pt-N) bonding and π-π bonding. The Pt colloids were prepared through ethanol reduction under the protection of aniline, the CNT was dispersed well with the existence of aniline in the solution, and aniline was polymerized in the presence of a protonic acid (HCl) and an oxidant (NH(4)S(2)O(8)). The synthesized PANI is found to wrap around the CNT as a result of π-π bonding, and highly dispersed Pt nanoparticles are loaded onto the CNT with narrowly distributed particle sizes ranging from 2.0 to 4.0 nm due to the polymer stabilization and existence of Pt-N bonding. The Pt-PANI/CNT catalysts are electroactive and exhibit excellent electrochemical stability and therefore promise potential applications in proton exchange membrane fuel cells.

A facile strategy for ultrasmall Pt NPs being partially-embedded in N-doped carbon nanosheet structure for efficient electrocatalysis

“…. . 4p (521 eV) and Pt 4d (316 and 333 eV) also appear [15,24]. The average contents of elements in CpPy-NS and CpPy-NS@500 are summarized in Table S1, from which the atomic percentage of N decreases after being annealed at 500°C due to the dissociation of ammonia molecule coordinated to Pt in cisplatin upon heating at elevated temperatures.…”

“…Among them, the pyrrolic and graphitic N species can promote the oxygen reduction via changing the chemical/electronic environment of the neighboring carbon atoms [32][33][34]. Besides, a lower binding energy of 398.5 eV may be attributed to the interaction between Pt and N atoms [15,16].…”

“…As previously reported [12][13][14], the metal NP embedded in carbon support can achieve high electrocatalytic activity through altering the electronic structure of the active sites, and much enhanced durability performance as well. However, surfactants, organic stabilizing agents, and the complicated procedures are usually necessary to obtain the uniform distribution and embedding of metal NP onto/into the carbon supports matrix [15][16][17][18]. Although they could lead to excellent durability performance via stabilizing and steric effect, the confined Pt NPs in carbon surface layer will sacrifice a large proportion of active sites [19,20].…”

Preparation of Polyaniline Covalently Grafted Carbon Nanotubes Supported Pt Catalysts and Its Electrocatalytic Performance for Methanol

“…纯 Pt 很容易被甲醇电氧化的中间产物 CO 毒化, 使 得催化活性降低 [26] . 经 XPS 研究证实聚苯胺中氮的孤对电子可与 Pt 原子的 空轨道在 397.6 eV 处形成 Pt-N 共价键, 这种共价键的 存在可增强 Pt 与 PANI 的作用力, 因而从整体上提高了 Pt/CNTs-NH-PANI 催化剂的稳定性 [36] . …”

Bimetallic PtRu Nanoparticles Supported on Functionalized Multiwall Carbon Nanotubes as High Performance Electrocatalyst for Direct Methanol Fuel Cells

“…For instance, to promote the distribution of nanoparticles on the supports, some additional stabilizers such as polyaniline (PANI) and polypyrrole (PPy) are introduced on the surface of the supports. 16,17 On one hand, modifying with organic molecules could improve the dispersion of Pt-based catalysts; on the other hand, these organic additives might block the active sites on the Pt-based catalysts and reduce the conductivity of the catalyst. Besides, for the bimetallic catalysts, it is necessary to optimize the methanol oxidation reaction by accurate control over the atom ratio and support surface.…”