Mesoporous Pt@Pt-skin Pt3Ni core-shell framework nanowire electrocatalyst for efficient oxygen reduction

Abstract

The design of Pt-based nanoarchitectures with controllable compositions and morphologies is necessary to enhance their electrocatalytic activity. Herein, we report a rational design and synthesis of anisotropic mesoporous Pt@Pt-skin Pt3Ni core-shell framework nanowires for high-efficient electrocatalysis. The catalyst has a uniform core-shell structure with an ultrathin atomic-jagged Pt nanowire core and a mesoporous Pt-skin Pt3Ni framework shell, possessing high electrocatalytic activity, stability and Pt utilisation efficiency. For the oxygen reduction reaction, the anisotropic mesoporous Pt@Pt-skin Pt3Ni core-shell framework nanowires demonstrated exceptional mass and specific activities of 6.69 A/mgpt and 8.42 mA/cm2 (at 0.9 V versus reversible hydrogen electrode), and the catalyst exhibited high stability with negligible activity decay after 50,000 cycles. The mesoporous Pt@Pt-skin Pt3Ni core-shell framework nanowire configuration combines the advantages of three-dimensional open mesopore molecular accessibility and compressive Pt-skin surface strains, which results in more catalytically active sites and weakened chemisorption of oxygenated species, thus boosting its catalytic activity and stability towards electrocatalysis.

A P-doped PtNi alloy supported on N,C-doped TiO2 nanosheets as a stable electrocatalyst for the oxygen reduction reaction in an acidic electrolyte

“…2I), which is consistent with the (111) plane of Pt–Ni alloy. 3 The composition line-scan profiles across the obtained P–PtNi NPs further confirmed the distribution of Pt and Ni elements throughout the NPs (Fig. S1D, ESI†).…”

“…2 Core–shell nanowires of Pt@Pt-skin Pt 3 Ni demonstrated high activity for the ORR. 3 Nevertheless, the stability of these Pt-based alloys remains a critical concern due to the dissolution of transition metals and oxidation corrosion of carbon supports under operating potential and acidic conditions, causing continuous degradation of the catalyst performance. In addition to traditional binary Pt–M alloys, it has been found that introducing a third element such as molybdenum (Mo), 4 indium (In), 5 phosphorus (P), 6 nitrogen (N), 7 or sulfur (S) 8 improved the catalysts’ stability, due to modulation of the electronic structure of the Pt NPs.…”

PtNi alloy nanoparticles grownin situon nitrogen doped carbon for the efficient oxygen reduction reaction

“…For example, the half wave potential of the Pt 3 Ni NPs moved 100 mV positively compared with the commercial Pt/C catalyst due to increased active sites for O 2 adsorption. 10,16 Besides, the electrochemically active sites of Pt atoms will be exposed and adjusted sufficiently by engineering the Pt–Ni alloy nanostructure, which reduced Pt–Pt spacing and accelerated the oxygen dissociation adsorption, enhancing ORR performance substantially. 11 However, the stability remains a problem owing to the leaching of Ni in a strong acidic electrolyte at high potentials.…”

“…12–14 Thus, PtNi alloy NPs with Pt-skin were usually engineered. 15,16 For example, Jin et al reported a mesoporous Pt@Pt-skin Pt 3 Ni core–shell framework nanowire, which had 15 times higher MA than the standard of the 2020 U.S. Department of Energy (DOE) target with a negligible loss after 50 000 potential-scanning cycles. 16…”

Block-Polymer-Restricted Sub-nanometer Pt Nanoclusters Nanozyme-Enhanced Immunoassay for Monitoring of Cardiac Troponin I

“…Nanozymes, as nanomaterials with enzyme-mimicking activity under physiologically relevant conditions, are gradually becoming a star product to replace natural enzymes for biologically relevant catalysis. – Considering the easy fabrication procedure, low synthesis cost, and good stability, nanozymes have emerged in applications, including molecular detection, in vivo therapy, and environmental treatment. – Currently, a number of nanomaterials, such as metals, metal oxides, carbon support materials, and metal–organic framework materials, have been identified to exhibit clear intrinsic enzyme-like activities. – Pt-based metallo-nanoparticles (NPs) are of great interest in disease diagnosis and treatment owing to their multienzyme-mimicking properties, in vivo stability, and biosafety. – Although several nanozymes have been developed to extend practical applications, their low catalytic efficiency and stability are still limiting factors for their development.…”