Searching General Sufficient‐and‐Necessary Conditions for Ultrafast Hydrogen‐Evolving Electrocatalysis. (25th March 2019)

• Record Type: Journal Article
• Authors: Guan, Daqin; Zhou, Jing; Hu, Zhiwei; Zhou, Wei; Xu, Xiaomin; Zhong, Yijun; Liu, Bo; Chen, Yuhui; Xu, Meigui; Lin, Hong‐Ji; Chen, Chien‐Te; Wang, Jian‐Qiang; Shao, Zongping
• Is Part Of: Advanced functional materials. Volume 29:Number 20(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-03-25
• Subjects: active sites -- hydrogen evolution reaction -- non‐noble metal perovskite oxides -- ordered oxygen vacancies -- oxygen 2p holes; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.201900704
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: The development of cost‐effective and high‐performance electrocatalysts for the hydrogen evolution reaction (HER) is one critical step toward successful transition into a sustainable green energy era. Different from previous design strategies based on single parameter, here the necessary and sufficient conditions are proposed to develop bulk non‐noble metal oxides which are generally considered inactive toward HER in alkaline solutions: i) multiple active sites for different reaction intermediates and ii) a short reaction path created by ordered distribution and appropriate numbers of these active sites. Computational studies predict that a synergistic interplay between the ordered oxygen vacancies (at pyramidal high‐spin Co 3+ sites) and the O 2p ligand holes (OLH; at metallic octahedral intermediate‐spin Co 4+ sites) in RBaCo2 O5.5+ δ (δ = 1/4; R = lanthanides) can produce a near‐ideal HER reaction path to adsorb H2 O and release H2, respectively. Experimentally, the as‐synthesized (Gd0.5 La0.5 )BaCo2 O5.75 outperforms the state‐of‐the‐art Pt/C catalyst in many aspects. The proof‐of‐concept results reveal that the simultaneous possession of ordered oxygen vacancies and an appropriate number of OLH can realize a near‐optimal synergistic catalytic effect, which is pivotal for rational design of oxygen‐containing materials. Abstract : The necessary and sufficient conditions to design highly active hydrogen‐evolving electrocatalysts are proposed: i) multiple active sites for various reaction intermediates and ii) a short reaction path. The as‐synthesized (Gd0.5 La0.5 )BaCo2 O5.75 material, with ordered oxygen vacancies and an appropriate number of oxygen 2p holes, achieves a near‐optimal synergistic catalytic effect and makes a breakthrough in the activity of non‐noble metal oxides.