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The electrocatalytic value of nanoparticles has attracted substantial attention in relation to energy conversion devices, including solid oxide fuel cells. Among various forms of analogs, ex‐solved metal nanoparticles originating from their parent oxides display strong particle‐substrate interactions and thus have the benefits of extended durability and of course enhanced catalytic activity. Inspired by recent advances, here, novel air‐electrode materials based on BaCoO3–δ perovskites decorated with socketed Ag nanoparticles are presented. Doping with niobium (Nb5+) and tantalum (Ta5+) can significantly promote the stability of the cubic perovskite phase. The developed oxides exhibit promising performance outcomes in the highly prized low‐to‐intermediate temperature regimes (450–650 °C). Moreover, the exclusion of Ag particles further activates the parent scaffold, thereby conveying record‐level area‐specific resistance (e.g., ≈0.02 Ω cm2 at 650 °C). Coupled with the unique nanoarchitecture, the newly designed cathode showcases in this study hold great promise for future air‐electrodes in fuel cells. [ABSTRACT FROM AUTHOR]

High cost and low durability are unresolved issues that impede the commercialization of proton exchange membrane fuel cells (PEMFCs). To overcome these limitations, Pt/TiO 2 is reported as an alternative electrocatalyst for enhancing the oxygen reduction reaction (ORR) activity and/or durability of the system. However, the low electrical conductivity of TiO 2 is a drawback that may be addressed by doping. To date, most reports related to Pt/doped-TiO 2 focus on changes in the catalyst activity caused by the Pt-TiO 2 interaction (metal-support interaction), instead of the effect of doping itself; doping is merely considered to enhance the electrical conductivity of TiO 2 . In this study, we discuss the variation in the electronic fine structure of Pt caused by the dopant, and its correlation with the ORR activity. More extensive contraction of the Pt lattice in Pt/M-TiO 2 (M = V, Cr, and Nb) relative to Pt/TiO 2 and Pt/C leads to outstanding ORR specific activity of Pt/M-TiO 2 . Notably, a fourfold increase of the specific activity is achieved with Pt/V-TiO 2 relative to Pt/C. Furthermore, an accelerated durability test (ADT) of Pt/V-TiO 2 demonstrates that this system is three times more durable than conventional Pt/C due to the metal-support interaction. [ABSTRACT FROM AUTHOR]

A challenging issue in the commercialization of fuel cells is to improve the kinetics of the sluggish oxygen reduction reaction (ORR) and durability of the cathode electrocatalyst under corrosive ORR conditions. In this paper, we report a promising approach to address these two major issues by Cr doping of TiO2 supports in Pt-based electrocatalysts. It was clearly revealed that Cr doping led to a marked enhancement of ORR kinetics, which was attributed to the compressive strain in the Pt lattice as well as the increased electronic conductivity of the Cr-TiO2 supports. Furthermore, Pt/Cr-TiO2 demonstrated a far superior durability to that of conventional Pt/C, which was assessed by accelerated durability tests (ADT) and in situ X-ray absorption near-edge structure studies. The specific activity of Pt/C decreased by 43 % after the ADT (141 μA cm−2 and 82 μA cm−2 before and after ADT, respectively), whereas that of Pt/Cr-TiO2 was merely reduced by 13 % (472 μA cm−2 and 409 μA cm−2). [ABSTRACT FROM AUTHOR]

Highlights: [•] The origin for ORR activity in Pt on titania has been in significant debate. [•] We resolve this controversy by considering a lattice strain effect. [•] The main origin is the compressive strain rather than the charge transfer. [Copyright &y& Elsevier]

Ex-Solved Ag Nanocatalysts: Ex-Solved Ag Nanocatalysts on a Sr-Free Parent Scaffold Authorize a Highly Efficient Route of Oxygen Reduction (Adv. Funct. Keywords: Ag; BaCoO3- ; ex-solution; oxygen reduction reaction; solid oxide fuel cells EN Ag BaCoO3- ex-solution oxygen reduction reaction solid oxide fuel cells 1 1 1 07/04/20 20200702 NES 200702 In article number 2001326, WooChul Jung and co-workers utilize a Ag ex-solution as the central strategy to demonstrate impressive oxygen reduction catalytic activity on BaCoO SB 3- sb perovskites. Ag, BaCoO3- , ex-solution, oxygen reduction reaction, solid oxide fuel cells. [Extracted from the article]