Conformation-modulated three-dimensional electrocatalysts for high-performance fuel cell electrodes

Abstract

Unsupported Pt electrocatalysts demonstrate excellent electrochemical stability when used in polymer electrolyte membrane fuel cells; however, their extreme thinness and low porosity result in insufficient surface area and high mass transfer resistance. Here, we introduce three-dimensionally (3D) customized, multiscale Pt nanoarchitectures (PtNAs) composed of dense and narrow (for sufficient active sites) and sparse (for improved mass transfer) nanoscale building blocks. The 3D-multiscale PtNA fabricated by ultrahigh-resolution nanotransfer printing exhibited excellent performance (45% enhanced maximum power density) and high durability (only 5% loss of surface area for 5000 cycles) compared to commercial Pt/C. We also theoretically elucidate the relationship between the 3D structures and cell performance using computational fluid dynamics. We expect that the structure-controlled 3D electrocatalysts will introduce a new pathway to design and fabricate high-performance electrocatalysts for fuel cells, as well as various electrochemical devices that require the precision engineering of reaction surfaces and mass transfer.

A clicking confinement strategy to fabricate transition metal single-atom sites for bifunctional oxygen electrocatalysis

“…The development of the modern society is propelled by the renewal and iteration of high-efficiency energy storage techniques (1)(2)(3)(4)(5). Beyond the current lithium-ion batteries, rechargeable zinc-air batteries (ZABs) are regarded as promising next-generation energy storage devices because of their high theoretical energy density (1086 Wh kg −1 , including oxygen) (6,7), low cost (8), inherent safety (using aqueous electrolyte) (9,10), and potential feasibility to achieve high rates and long cycling life span (11).…”

Block Copolymer Nanopatterning for Nonsemiconductor Device Applications

“…(e) Schematic illustration and SEM image of multiscale Pt nanoarchitectures. [Reprinted with permission from ref . Copyright 2021, American Association for the Advancement of Science.…”

“…Kim et al successfully demonstrated a high-performance multistacked three-dimensional (3D) Pt catalyst system by introducing Pt nanowires multiple transfer printed on a target substrate. 85 The loading amount and surface area of the resultant catalyst can be modulated to the same level as the commercial Pt/C catalyst (Figure 6c). Usually, conventional catalysts need further support, such as conductive carbon for the electron pathway during the reaction.…”

Enhanced oxygen transport in ionomer films on platinum electrodes via a local electric field

“…5–9 However, the high oxygen transport resistance at a low Pt loading severely decreases the performance of PEMFCs. 10–12 Density functional theory (DFT) calculations have been employed to understand the underlying mechanisms and optimize the electrodes for enhancing electrochemical reactions. He et al 5 calculated the electronic structure change of catalyst supports when in contact with Pt using DFT calculations and these DFT calculation can serve as an effective screening tool of catalyst supports.…”