In situ construction of Ir@Pt/C nanoparticles in the cathode layer of membrane electrode assemblies with ultra-low Pt loading and high Pt exposure

Abstract

A novel membrane electrode assemblies (MEAs) with ultra-low Pt loadings and high Pt exposure in the cathode layer is prepared by spraying Ir/C catalyst ink on the membrane surface to form a substrate layer, followed by in situ pulse electrochemical deposition of a Pt shell layer on the Ir core nanoparticles in the substrate layer. It makes the Pt loadings on cathode lower to 0.044mg/cm 2. In our system, the MEA with our novel cathode exhibits excellent performance in a H 2 /air single fuel cell, which is comparable to that of the MEA prepared with commercial Pt/C catalyst (Johnson Matthey 40% Pt) with Pt loadings of 0.1mg/cm 2. The electrode with core-shell structured catalysts is characterized by X-ray diffraction, X-ray photoelectron spectroscopy, EDS line-scan, and scanning transmission electron microscopy. Based on the characterization results, it is found that the Pt is highly dispersed on the Ir NPs, and the electronic feature of Pt at shell layer can be tuned by

Global research direction on Pt and Pt based electro‐catalysts for fuel cells application between 1990 and 2019: A bibliometric analysis

“…At low loading, Pt corrosion or dissolution are hardly tolerated and they affect fuel cell performance 9 . A large proportion of Pt catalyst in a normal membrane electrode assemblies (MEAs) in a fuel cell is wasted because of: (a) Pt catalyst may be hidden in the solid electrolyte film because of the binder used to prepare the layer of the catalyst 10 (b) active Pt nanoparticles embedded in carbon powder stayed isolated from the solid electrolyte. To attain fuel cell commercialisation, Pt loadings must be drastically reduced in the electrode from the level of a few mg cm −2 presently to less than 0.1 mg cm −2 10 .…”

Engineering Ruthenium-Based Electrocatalysts for Effective Hydrogen Evolution Reaction

“…Platinum (Pt) is the most effective HER catalyst, while its wide application is limited due to its high cost and low reserves [5][6][7][8]. In the past few decades, several non-noble metal catalysts or metal-free catalysts have been developed for the HER, but their poor activity and stability still cannot meet the requirements to replace Pt-based catalysts [9][10][11][12][13].…”

Advanced Atomically Dispersed Metal–Nitrogen–Carbon Catalysts Toward Cathodic Oxygen Reduction in PEM Fuel Cells

“…[ 3,4 ] Proton exchange membrane fuel cells (PEMFCs) are fuel cells that can convert the chemical energy of hydrogen and oxygen into electrical energy by electrochemical reactions (hydrogen oxidation reaction, HOR; and oxygen reduction reaction, ORR); and they have the advantages of zero carbon emissions, high power density, fast start‐up, and low operating temperatures, and show a great potential for application in transportation and stationary energy systems. [ 5–8 ] Unfortunately, because the ORR occurring at cathodic side suffers from slow kinetics which is more than five orders of magnitude slower than that of the HOR, a large number of platinum‐group metal (PGM) based catalysts are required to promote the reaction. [ 9–11 ] The scarcity and high price of PGM results in the high cost of PEMFCs, hampering their large‐scale commercial applications.…”