Testing PtCu Nanoparticles Supported on Highly Ordered Mesoporous Carbons CMK3 and CMK8 as Catalysts for Low-Temperature Fuel Cells

Abstract

Pt(Cu) nanoparticles supported on CMK3 and CMK8 ordered mesoporous carbons (OMCs) have been synthesized by electroless deposition of Cu followed by galvanic exchange with Pt. The structural characterization by high-resolution transmission electron microscopy and X-ray diffraction showed the formation of Pt(Cu) nanoparticles of 4–5 nm, in which PtCu alloys with contracted fcc Pt lattice and 70–80 at.% Pt was identified. The X-ray photoelectron spectroscopy analyses indicated that the Pt(Cu) nanoparticles were mainly composed of a PtCu alloy core covered by a Pt-rich shell, in agreement with the steady cyclic voltammograms, which did not show any Cu oxidation peaks. Electroactive surface areas up to about 70 m2 gPt−1 were obtained. The onset potentials for CO oxidation and the oxygen reduction reaction were more negative and positive, respectively, as compared to Pt/C, thus indicating higher activity of these Pt(Cu) catalysts with respect to the latter. Based on the corresponding binding energies, these better activities were attributed to the favorable geometric and ligand effects of Cu on Pt, which were able to reduce the adsorption energy of the intermediates on Pt. Pt(Cu)/CMK3 showed competitive mass and specific activities, as well as better stability than Pt/C.

Review and Development of Anode Electrocatalyst Carriers for Direct Methanol Fuel Cell

“…Its surface is rich in oxygen-containing functional groups, and these groups improve the interaction between the active component and the carrier through the oxidation and removal of CO and other reaction intermediates to achieve better antipoisoning ability. [36][37][38] It has important application prospects in adsorption and separation, catalyst carriers, and electronic devices. Lo et al synthesized highly dispersed Pt-RuOu-SnOv nanoparticles using mesoporous carbon CMK-3 as a carrier, and the best Pt-based catalysts were obtained by modulating the electronic structure by varying the content of Ru and Sn.…”

Nanostructuring determines poisoning: tailoring CO adsorption on PtCu bimetallic nanoparticles

“…25,[49][50][51][52] For small PtCu NPs (2-5 nm), obtained also by galvanic displacement of Cu by Pt on different carbon supports, X-ray photoelectron spectroscopy (XPS) analyses with different Ar + sputtering times were performed. 25,[49][50][51][52] Interestingly, the XPS results showed that the Pt(0):Cu(0) ratio decreased when increasing the sputtering time, thus strongly indicating a Pt surface enrichment. Thus, the NPs can be described as having core@shell structures with a PtCu alloy core and a shell mainly composed of Pt atoms.…”

“…Besides, the size of the NPs studied in this paper was too small to detect Pt and Cu concentration gradients along the NP diameter (line profile) by energy-dispersive X-ray spectroscopy (EDS) because of insufficient spatial resolution of the technique. 25,[49][50][51][52] For small PtCu NPs (2-5 nm), obtained also by galvanic displacement of Cu by Pt on different carbon supports, X-ray photoelectron spectroscopy (XPS) analyses with different Ar + sputtering times were performed. 25,[49][50][51][52] Interestingly, the XPS results showed that the Pt(0):Cu(0) ratio decreased when increasing the sputtering time, thus strongly indicating a Pt surface enrichment.…”

Copper(i) as a reducing agent for the synthesis of bimetallic PtCu catalytic nanoparticles

“…The interest in copper (Cu) being used in combination with different metals, such as gold, palladium, platinum or silver, has increased in recent years. [22][23][24] The presence of copper can decrease the cost of the catalyst and improve the catalytic activity in many reactions, i.e. selective hydrogenolysis of biomass-derived glycerol or reduction of 4-nitrophenol by NaBH 4 .…”