Atomically dispersed Fe/Bi dual active sites single-atom nanozymes for cascade catalysis and peroxymonosulfate activation to degrade dyes

2022 ◽  
Vol 422 ◽  
pp. 126929 ◽  
Author(s):  
Qiumeng Chen ◽  
Yuan Liu ◽  
Yuwan Lu ◽  
Yuejie Hou ◽  
Xiaodan Zhang ◽  
...  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yanming Cai ◽  
Jiaju Fu ◽  
Yang Zhou ◽  
Yu-Chung Chang ◽  
Qianhao Min ◽  
...  

AbstractSingle-atom catalysts (SACs) are promising candidates to catalyze electrochemical CO2 reduction (ECR) due to maximized atomic utilization. However, products are usually limited to CO instead of hydrocarbons or oxygenates due to unfavorable high energy barrier for further electron transfer on synthesized single atom catalytic sites. Here we report a novel partial-carbonization strategy to modify the electronic structures of center atoms on SACs for lowering the overall endothermic energy of key intermediates. A carbon-dots-based SAC margined with unique CuN2O2 sites was synthesized for the first time. The introduction of oxygen ligands brings remarkably high Faradaic efficiency (78%) and selectivity (99% of ECR products) for electrochemical converting CO2 to CH4 with current density of 40 mA·cm-2 in aqueous electrolytes, surpassing most reported SACs which stop at two-electron reduction. Theoretical calculations further revealed that the high selectivity and activity on CuN2O2 active sites are due to the proper elevated CH4 and H2 energy barrier and fine-tuned electronic structure of Cu active sites.


2021 ◽  
Author(s):  
Hongling Yang ◽  
Xun Zhang ◽  
Yi Yu ◽  
Zheng Chen ◽  
Qinggang Liu ◽  
...  

Single-atom catalysts provide a pathway to elucidate the nature of catalytically active sites. However, keeping them stabilized during operation proves to be challenging. Herein, we employ cryptomelane-type octahedral molecular sieve...


2021 ◽  
Author(s):  
Changhyeok Choi ◽  
Sungho Yoon ◽  
Yousung Jung

The scaling relationship of methane activation via a radical-like transition state shifts toward a more reactive region with decreasing coordination number of the active sites.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Panlong Zhai ◽  
Mingyue Xia ◽  
Yunzhen Wu ◽  
Guanghui Zhang ◽  
Junfeng Gao ◽  
...  

AbstractRational design of single atom catalyst is critical for efficient sustainable energy conversion. However, the atomic-level control of active sites is essential for electrocatalytic materials in alkaline electrolyte. Moreover, well-defined surface structures lead to in-depth understanding of catalytic mechanisms. Herein, we report a single-atomic-site ruthenium stabilized on defective nickel-iron layered double hydroxide nanosheets (Ru1/D-NiFe LDH). Under precise regulation of local coordination environments of catalytically active sites and the existence of the defects, Ru1/D-NiFe LDH delivers an ultralow overpotential of 18 mV at 10 mA cm−2 for hydrogen evolution reaction, surpassing the commercial Pt/C catalyst. Density functional theory calculations reveal that Ru1/D-NiFe LDH optimizes the adsorption energies of intermediates for hydrogen evolution reaction and promotes the O–O coupling at a Ru–O active site for oxygen evolution reaction. The Ru1/D-NiFe LDH as an ideal model reveals superior water splitting performance with potential for the development of promising water-alkali electrocatalysts.


Author(s):  
Danni Zhou ◽  
Xinyuan Li ◽  
Huishan Shang ◽  
Fengjuan Qin ◽  
Wenxing Chen

Metal-organic framework (MOF) derived single-atom catalysts (SACs), featured unique active sites and adjustable topological structures, exhibit high electrocatalytic performance on carbon dioxide reduction reactions (CO2RR). By modulating elements and atomic...


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Guokang Han ◽  
Xue Zhang ◽  
Wei Liu ◽  
Qinghua Zhang ◽  
Zhiqiang Wang ◽  
...  

AbstractSingle-atom catalysts are becoming increasingly significant to numerous energy conversion reactions. However, their rational design and construction remain quite challenging due to the poorly understood structure–function relationship. Here we demonstrate the dynamic behavior of CuN2C2 site during operando oxygen reduction reaction, revealing a substrate-strain tuned geometry distortion of active sites and its correlation with the activity. Our best CuN2C2 site, on carbon nanotube with 8 nm diameter, delivers a sixfold activity promotion relative to graphene. Density functional theory and X-ray absorption spectroscopy reveal that reasonable substrate strain allows the optimized distortion, where Cu bonds strongly with the oxygen species while maintaining intimate coordination with C/N atoms. The optimized distortion facilitates the electron transfer from Cu to the adsorbed O, greatly boosting the oxygen reduction activity. This work uncovers the structure–function relationship of single-atom catalysts in terms of carbon substrate, and provides guidance to their future design and activity promotion.


Author(s):  
Ruonan Zhan ◽  
Yufei Zhou ◽  
Cong Liu ◽  
Xiaojing Wang ◽  
Xiaoli Sun ◽  
...  
Keyword(s):  

2019 ◽  
Vol 131 (34) ◽  
pp. 11994-11999 ◽  
Author(s):  
Wei‐Hong Lai ◽  
Li‐Fu Zhang ◽  
Wei‐Bo Hua ◽  
Sylvio Indris ◽  
Zi‐Chao Yan ◽  
...  

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Xi Zhang ◽  
Guoqing Cui ◽  
Haisong Feng ◽  
Lifang Chen ◽  
Hui Wang ◽  
...  

AbstractSelective hydrogenolysis of biomass-derived glycerol to propanediol is an important reaction to produce high value-added chemicals but remains a big challenge. Herein we report a PtCu single atom alloy (SAA) catalyst with single Pt atom dispersed on Cu nanoclusters, which exhibits dramatically boosted catalytic performance (yield: 98.8%) towards glycerol hydrogenolysis to 1,2-propanediol. Remarkably, the turnover frequency reaches up to 2.6 × 103 molglycerol·molPtCu–SAA−1·h−1, which is to our knowledge the largest value among reported heterogeneous metal catalysts. Both in situ experimental studies and theoretical calculations verify interface sites of PtCu–SAA serve as intrinsic active sites, in which the single Pt atom facilitates the breakage of central C–H bond whilst the terminal C–O bond undergoes dissociation adsorption on adjacent Cu atom. This interfacial synergistic catalysis based on PtCu–SAA changes the reaction pathway with a decreased activation energy, which can be extended to other noble metal alloy systems.


2019 ◽  
Vol 7 (46) ◽  
pp. 26231-26237 ◽  
Author(s):  
Fuping Pan ◽  
Hanguang Zhang ◽  
Zhenyu Liu ◽  
David Cullen ◽  
Kexi Liu ◽  
...  

Active sites of single-atom nickel catalysts for CO2 reduction were revealed to be edge-located Ni–N2+2 sites with dangling bond-containing carbon atoms, which facilitate the dissociation of the C–O bond of *COOH intermediate.


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