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04 Sep 02:35

[ASAP] Engineering of Coordination Environment and Multiscale Structure in Single-Site Copper Catalyst for Superior Electrocatalytic Oxygen Reduction

by Tingting Sun†‡?, Yinlong Li§?, Tingting Cui‡?, Lianbin Xu?, Yang-Gang Wang§, Wenxing Chen?, Pianpian Zhang†, Tianyu Zheng†, Xianzhang Fu†, Shaolong Zhang‡, Zedong Zhang‡, Dingsheng Wang*‡, and Yadong Li‡

TOC Graphic

Nano Letters
DOI: 10.1021/acs.nanolett.0c02677
04 Sep 00:33

Adapt taxonomy to conservation goals

by O'Connell, D. P., Kelly, D. J., Analuddin, K., Karya, A., Marples, N. M., Martin, T. E.
19 Jul 07:03

[ASAP] One-Pot Photomediated Giese Reaction/Friedel–Crafts Hydroxyalkylation/Oxidative Aromatization To Access Naphthalene Derivatives from Toluenes and Enones

by Haiwang Liu, Lishuang Ma, Rong Zhou, Xuebo Chen, Weihai Fang, Jie Wu

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ACS Catalysis
DOI: 10.1021/acscatal.8b00481
30 Oct 06:09

Platinum-Based Nanowires as Active Catalysts toward Oxygen Reduction Reaction: In Situ Observation of Surface-Diffusion-Assisted, Solid-State Oriented Attachment

by Yanling Ma, Wenpei Gao, Hao Shan, Wenlong Chen, Wen Shang, Peng Tao, Chengyi Song, Chris Addiego, Tao Deng, Xiaoqing Pan, Jianbo Wu

Abstract

Facile fabrication of advanced catalysts toward oxygen reduction reaction with improving activity and stability is significant for proton-exchange membrane fuel cells. Based on a generic solid-state reaction, this study reports a modified hydrogen-assisted, gas-phase synthesis for facile, scalable production of surfactant-free, thin, platinum-based nanowire-network electrocatalysts. The free-standing platinum and platinum–nickel alloy nanowires show improvements of up to 5.1 times and 10.9 times for mass activity with a minimum 2.6% loss after an accelerated durability test for 10k cycles; 8.5 times and 13.8 times for specific activity, respectively, compared to commercial Pt/C catalyst. In addition, combined with a wet impregnation method, different substrate-materials-supported platinum-based nanowires are obtained, which paves the way to practical application as a next-generation supported catalyst to replace Pt/C. The growth stages and formation mechanism are investigated by an in situ transmission electron microscopy study. It reveals that the free-standing platinum nanowires form in the solid state via metal-surface-diffusion-assisted oriented attachment of individual nanoparticles, and the interaction with gas molecules plays a critical role, which may represent a gas-molecular-adsorbate-modified growth in catalyst preparation.

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Free-standing platinum and platinum–nickel alloy nanowires are synthesized by a modified facile hydrogen-assisted gas-phase method. In situ transmission electron microscopy observation reveals that the formation of nanowires is attributed to surface-diffusion-assisted, solid-state oriented attachment. The Pt and Pt1.3Ni-alloy nanowires exhibit promising catalytic activity and excellent stability compared with commercial Pt/C toward oxygen reduction reaction.

02 Dec 06:55

Materials design by evolutionary optimization of functional groups in metal-organic frameworks

by Collins, S. P., Daff, T. D., Piotrkowski, S. S., Woo, T. K.

A genetic algorithm that efficiently optimizes a desired physical or functional property in metal-organic frameworks (MOFs) by evolving the functional groups within the pores has been developed. The approach has been used to optimize the CO2 uptake capacity of 141 experimentally characterized MOFs under conditions relevant for postcombustion CO2 capture. A total search space of 1.65 trillion structures was screened, and 1035 derivatives of 23 different parent MOFs were identified as having exceptional CO2 uptakes of >3.0 mmol/g (at 0.15 atm and 298 K). Many well-known MOF platforms were optimized, with some, such as MIL-47, having their CO2 adsorption increase by more than 400%. The structures of the high-performing MOFs are provided as potential targets for synthesis.

28 Dec 01:13

A highly efficient electrocatalyst for oxygen reduction reaction: phosphorus and nitrogen co-doped hierarchically ordered porous carbon derived from an iron-functionalized polymer.

by Deng C, Zhong H, Li X, Yao L, Zhang H
Related Articles

A highly efficient electrocatalyst for oxygen reduction reaction: phosphorus and nitrogen co-doped hierarchically ordered porous carbon derived from an iron-functionalized polymer.

Nanoscale. 2015 Dec 22;

Authors: Deng C, Zhong H, Li X, Yao L, Zhang H

Abstract
Heteroatom-doped carbon materials have shown respectable activity for the oxygen reduction reaction (ORR) in alkaline media. However, the performances of these materials are not satisfactory for energy conversion devices, such as fuel cells. Here, we demonstrate a new type of phosphorus and nitrogen co-doped hierarchically ordered porous carbon (PNHOPC) derived from an iron-functionalized mesoporous polymer through an evaporation-induced self-assembly process that simultaneously combines the carbonization and nitrogen doping processes. The soft template and the nitrogen doping process facilitate the formation of the hierarchically ordered structure for the PNHOPC. The catalyst possesses a large surface area (1118 cm(2) g(-1)) and a pore volume of 1.14 cm(3) g(-1). Notably, it exhibits excellent ORR catalytic performance, superior stability and methanol tolerance in acidic electrolytes, thus making the catalyst promising for fuel cells. The correlations between the unique pore structure and the nitrogen and phosphorus configuration of the catalysts with high catalytic activity are thoroughly investigated.

PMID: 26692228 [PubMed - as supplied by publisher]

18 Nov 03:22

The application of graphene and its composites in oxygen reduction electrocatalysis: a perspective and review of recent progress

Energy Environ. Sci., 2015, Advance Article
DOI: 10.1039/C5EE02474A, Review Article
Drew Higgins, Pouyan Zamani, Aiping Yu, Zhongwei Chen
This paper provides a critical review and perspective on progress realized recently towards the development of graphene-based oxygen reduction catalysts.
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