Advanced Platinum-Based Oxygen Reduction Electrocatalysts for Fuel Cells

Abstract

Conspectus Fuel cells are among the cutting-edge energy technologies. Their commercial development is still hindered by noble platinum (Pt) catalysts for the oxygen reduction reaction (ORR) at the cathode, which not only determine the energy conversion efficiency and service life but also are closely related to the cost and broad application of fuel cells. Given the bright and enormous future of fuel cells, ORR catalysts should possess highly efficient performance yet meet the acceptable Pt costs for large-scale application. Extensive efforts are concentrated on the optimization of Pt-based nanostructures and upgradation of functional carriers to achieve the low-cost and high-activity Pt-based catalysts. By improving the Pt utilization and accessible surface, reducing Pt consumption and catalyst costs, accelerating mass exchange and electron transfer, alleviating the corrosion and agglomeration of carriers and Pt, accompanying with the assistance of robust yet effective functional supports, the service level and life of Pt-based electrocatalysts would be significantly improved and fuel cells could get into commercial market covering broader applications. In this Account, we focus on the recent development of Pt-based catalysts to figure out the problems associated with ORR catalysts in fuel cells. Recent development of Pt-based catalysts is discussed in different stages: (1) multiscale development of Pt-based nanostructures; (2) multielement regulation over Pt-based alloy composition; (3) upgradation of carbon and noncarbon support architectures; (4) development of integrated Pt-based catalysts for fuel cells. Finally, we propose some future issues (such as reaction mechanism, dynamic evolutions, and structure–activity relationship) for Pt-based catalysts, which mainly involve the preparation strategy of Pt-integrated catalysts (combination of Pt nanostructures with nanocarbons), performance evaluation (standard measurement protocols, laboratory-level rotating disk electrode (RDE) measurements, application-level membrane electrode assembly (MEA) service test), advanced interpretation techniques (spectroscopy, electron microscopy, and in situ monitoring), and cutting-edge simulation/calculations and artificial intelligence (simulation, calculations, machine learning, big data screening). This Account calls for the comprehensive development of multiscale, multicomponent, and high-entropy Pt-based alloy nanostructures, and novel and stable carriers, which provide more available options for rational design of low-cost and high-performance Pt-integrated ORR catalysts. More importantly, it will give an in-depth understanding of the reaction mechanism, dynamic development, and structure–performance relationship for Pt-based catalysts in fuel cells and related energy technologies.

Oxygen Reduction Electrocatalysts toward Practical Fuel Cells: Progress and Perspectives

“…Moreover,the fabrication of controllable synthesis through fine-tuning catalyst morphologies,a nd the subsequent preparation of catalyst layers for the realistic application in fuel cells is highly demanding. [148] These methods provide adaptable and matching testing conditions to practical fuel cells, which can be employed at broad range conditions with different Pt loading, variable catalyst layers thickness to get higher current density.S imilarly,s uch techniques with similar operating conditions would help in quick evaluation and screening of the activity and stability for the service and failure of catalysts in fuel cells. vii) Advanced characterization.…”

Oxygen Reduction Electrocatalysts toward Practical Fuel Cells: Progress and Perspectives

“…Therefore, this method can be an optimal supplement to drastically shorten the time from successful catalyst synthesis to an operating electrode for fuel cell applications. Similarly, floating electrode technique has been also used to balance the RDE and MEA testing conditions to overcome the existing gaps between RDE screening and MEA testing [148] . These methods provide adaptable and matching testing conditions to practical fuel cells, which can be employed at broad range conditions with different Pt loading, variable catalyst layers thickness to get higher current density.…”

Ultimate Corrosion to Pt‐Cu Electrocatalysts for Enhancing Methanol Oxidation Activity and Stability in Acidic Media

“…Alloying platinum with transition metals (M) reduces the usage of Pt and improves the electrocatalytic performances as compared with the pure Pt, which represents an established class of electrocatalysts. [1][2][3][4][5] However, one major fundamental and practical problem of PtM nanostructures is their low stability and durability, although studies so far have led to a considerable increase in electrocatalytic activity. The transition metals in these nanostructures gradually leach out under acidic operating condition, [6,7] which are needed to allow a high operation current density in the commercial polymer electrolyte membrane fuel cell (PEMFC).…”