Charge redistribution within platinum–nitrogen coordination structure to boost hydrogen evolution

Chen

Wang

et al. 2022

Adv Funct Materials

Single-atom catalysts (SACs) have attracted great attention in the field of electrocatalysis due to their exceptional activity, selectivity, 100% atom utilization, and tailorability of active sites at atomic level. The metal-support interactions and interatomic synergies, however, are severely limited due to the isolation of active sites in SACs which hinder their applications in some complex reactions. To this end, supported sub-nanometer cluster catalysts (SNCCs, <2 nm) with nearly fully exposed active atoms may outperform the SACs in some specific catalytic reactions. The presence of abundant chemical bonds in the clusters can flexibly regulate the support-cluster interaction and build ensemble effect in the sub-nanometer clusters for different electrocatalysis applications. In this review, recent advances of supported SNCCs in electrocatalysis applications are summarized and discussed for the first time. In particular, the importance of the support-cluster interactions and ensemble effect of the clusters in determining the catalytic performance of SNCCs are highlighted. Lastly, challenges and opportunities in SNCCs electrocatalysis are prospected.

Section: Support–cluster Interactionsmentioning

confidence: 99%

Section: Support–cluster Interactionsmentioning

confidence: 99%

Supported Sub‐Nanometer Clusters for Electrocatalysis Applications

Chen

Wang

et al. 2022

Adv Funct Materials

“…The producing clean hydrogen fuel through the electrochemical water splitting has been prove to be an efficient and environment-friendly strategy. − Platinum (Pt) electrocatalysts with different structures have been reported to be the highest efficient catalysts for hydrogen evolution reaction (HER) resulting from the moderate Pt–H bond strength. − However, high cost and scarcity of Pt remains a large obstacle for their large-scale commercial applications in electrochemical water splitting. − There are two main strategies to solve the challenges associated with using Pt electrocatalysts for HER. Developing earth-rich and no-noble metal-based HER nanomaterials including transition-metal phosphides and sulfides is a promising approach to achieve high active electrocatalysts for HER. − Although significant achievements have been made in the devolvement of these candidate nanomaterials, the Pt catalysts are still the best HER catalysts for industrial applications .…”

Section: Introductionmentioning

confidence: 99%

Structurally Ordered Pt₃Co Nanoparticles Anchored on N-Doped Graphene for Highly Efficient Hydrogen Evolution Reaction

Lin

Huang

ACS Sustainable Chem. Eng.

et al. 2020

Developing highly efficient catalysts for hydrogen evolution reaction (HER) play a significant role in the large-scale application of electrochemical water splitting. Here, we develop an ultrafine ordered Pt3Co NPs supported on N-doped graphene (NG), which achieves high HER activity with a small overpotential of 13 mV at 10 mA cm–2. More importantly, at the overpotential of 20 mV, the ordered Pt3Co catalyst (Pt3Co/NG-700) indicates 19.0 and 51.8 times mass activity than that of the disordered Pt3Co catalyst (Pt3Co/NG) and commercialized Pt/C catalyst, respectively. Additionally, the Pt3Co/NG-700 electrocatalyst displays outstanding long-term stability under harsh chronopotentiometry and cycling tests in the acidic media. The theory calculations reveal that the extraordinary HER performance on Pt3Co/NG-700 electrocatalyst originates from the charge redistribution of Pt induced by Co in the structurally ordered Pt3Co intermetallic. The charge redistribution of Pt facilitates the adsorption and dissociation of H* and provides a higher electron transfer and better conductivity, resulting in high HER. Our work opens new opportunities to design noble based alloy catalysts for highly efficient HER.

“…Specifically, the local coordination environment of metal atoms, including the oxidation state, the coordination number (CN), the coordination structure and so on, usually plays a significant role in electrical structure and charge diffusion dynamics of metal oxides. [4] Recently, several studies have been devoted to adjusting the coordination environment of metal atoms to regulate the performances of metal oxides based catalysis for oxygen evolution reaction, [4] hydrogen evolution reaction, [5] CO 2 reduction, [6] and organic oxidation. [7] However, the effect on the coordination environment of metal atoms on the capacitive performance of metal oxides, as far as we know, remains elusive.…”

mentioning

confidence: 99%

Adjusting the Coordination Environment of Mn Enhances Supercapacitor Performance of MnO₂

Advanced Energy Materials

Zhao

et al. 2021

105

delivers a low volumetric capacitance due to its insufficient active sites, as well as the existence of "dead volumes" without capacitance contribution. Especially, both the low conductivity and the poor ion transport ability of MnO 2 significantly hinder the charge transfer rate. [3] Therefore, it is highly desirable to improve the intrinsically electrical conductivity and ion diffusion ability aiming to achieve high performance of MnO 2 for supercapacitor applications.As known, electronic structure, as an important physical and chemical feature, significantly impacts the properties of metal oxide electrode materials. Consequently, optimized electronic structure of metal oxides has drawn dramatically attention in order to solve the problems of low electrical conductivity and poor ion diffusion ability. Specifically, the local coordination environment of metal atoms, including the oxidation state, the coordination number (CN), the coordination structure and so on, usually plays a significant role in electrical structure and charge diffusion dynamics of metal oxides. [4] Recently, several studies have been devoted to adjusting the coordination environment of metal atoms to regulate the performances of metal oxides based catalysis for oxygen evolution reaction, [4] hydrogen evolution reaction, [5] CO 2 reduction, [6] and organic oxidation. [7] However, the effect on the coordination environment of metal atoms on the capacitive performance of metal oxides, as far as we know, remains elusive. In particular, no effort has been made to tailoring electrochemical properties of MnO 2 as supercapacitor electrode material in considering adjusting the coordination environment of Mn atoms. Therefore, it is scientifically meaningful to optimize the coordination environment of Mn atoms, thus endowing MnO 2 electrode material with promising supercapacitor performances.Herein, MnO 2 -TEA nanosheets (NSs) were successfully prepared through a solution-based chemical deposition process using Triethanolamine (TEA) as a typical complex agent. Scanning transmission electron microscopy (STEM), X-ray photoelectron spectroscopy (XPS), and X-ray absorption spectroscopy (XAS) confirm that the coordination environment of Mn atoms in MnO 2 -TEA has been sufficiently adjusted by forming oxygen deficiency and more Mn-Mn2 (corner-shared Mn-Mn shell). As a result, the electrochemical performance of MnO 2 -TEA isThe electrochemical properties of transition metal oxides strongly depend on the coordination environment of metal atoms. Nevertheless, the relationship between the coordination environment of metal atoms and electrochemical performance of metal oxides is unclear, while the strategy of adjusting the coordination environment of metal atoms is rare. Herein, the engineering of the coordination environment of Mn atoms in manganese dioxides (MnO 2 ) by using a triethanolamine (TEA) complex-induced method is reported. The detailed experimental characterizations and density functional theory calculations show that the optimized Mn coordination e...