scholarly journals UMA BREVE REVISÃO SOBRE A CATÁLISE POR ÁTOMOS ISOLADOS: CONCEITOS E APLICAÇÕES

Química Nova ◽  
2021 ◽  
Author(s):  
Luanne Ferreira ◽  
Ruan Ribeiro ◽  
Vinicius Madriaga ◽  
Sancler Vasconcelos ◽  
Eric Shimabukuro ◽  
...  

A BRIEF OVERVIEW ON SINGLE-ATOM CATALYSIS: CONCEPTS AND APPLICATIONS. Catalytic processes became extremely important for the development of our society, especially after the second industrial revolution. Thus, the research for more efficient catalysts is an obstacle to overcome to achieve cheaper processes, higher yields, and selectivity of desired products. In this context, single-atom catalysis emerges as a promising alternative to unite the advantages of traditional homogeneous and heterogeneous catalysis. Catalysis by single-atoms is a bridge that unites in a single catalyst the ease of recovery and reuse (from heterogeneous catalysis) with the high exposure and uniformity of sites (from homogeneous catalysis). Thus, single-atom catalysts (SACs) and single-atom alloys (SAAs) have already found several applications in the literature, such as in hydrogenation, oxidation, conversion of biomass derivatives, electrocatalysis, and photocatalysis. However, it is essential to emphasize that it is still a field that is expanding and relatively new, with several opportunities and many barriers to surpass. In this review, concepts of homogeneous, enzymatic, and heterogeneous catalysis will be addressed, as well as fundamental aspects of single-atom catalysis, preparation methods, characterization, and current challenges.

Author(s):  
Yong Kang ◽  
Jianchen Wang

Owing to the 100% atom utilization and the potential in bridging the gap between homogeneous catalysis and heterogeneous catalysis, single-atom catalysts (SACs) have doubtlessly obtained a broad attention from both...


2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Yujing Ren ◽  
Yan Tang ◽  
Leilei Zhang ◽  
Xiaoyan Liu ◽  
Lin Li ◽  
...  

Abstract Heterogeneous single-atom catalyst (SAC) opens a unique entry to establishing structure–performance relationship at the molecular level similar to that in homogeneous catalysis. The challenge lies in manipulating the coordination chemistry of single atoms without changing single-atom dispersion. Here, we develop an efficient synthetic method for SACs by using ethanediamine to chelate Pt cations and then removing the ethanediamine by a rapid thermal treatment (RTT) in inert atmosphere. The coordination chemistry of Pt single atoms on a Fe2O3 support is finely tuned by merely adjusting the RTT temperature. With the decrease in Pt-O coordination number, the oxidation state of Pt decreases, and consequently the hydrogenation activity increases to a record level without loss of chemoselectivity. The tunability of the local coordination chemistry, oxidation states of the metal, and the catalytic performance of single atoms reveals the unique role of SACs as a bridge between heterogeneous and homogeneous catalysis.


Nanoscale ◽  
2021 ◽  
Author(s):  
Mengru Ren ◽  
Lili Zhang ◽  
Yan Di Zhu ◽  
Jin Lei Shi ◽  
Xing Ju Zhao ◽  
...  

Theoretical design and experimental fabrication of highly efficient single-atom catalysts (SACs) containing isolated metal atoms monodispersed on appropriate substrates have surged to the forefront of heterogeneous catalysis in recent years....


2021 ◽  
Author(s):  
Fengjuan Qin ◽  
Wenxing Chen

Compared with traditional catalysts, copper-based SAAs have high activity and stability in heterogeneous catalysis due to their special structures and interactions.


2021 ◽  
Author(s):  
Chuan Zhou ◽  
Jiayue Zhao ◽  
Peng Fei Liu ◽  
Jian-Fu Chen ◽  
Sheng Dai ◽  
...  

Given an oriented property, to locate the adequate material is always highly desired but very challenging in a range of applications including heterogeneous catalysis. Obviously, an object-oriented design/screening is an...


2020 ◽  
Author(s):  
Weihong Lai ◽  
Heng Wang ◽  
Quan jiang ◽  
Zichao Yan ◽  
Hanwen Liu ◽  
...  

<p>Herein, we develop a non-selective charge compensation strategy to prepare multi-single-atom doped carbon (MSAC) in which a sodium p-toluenesulfonate (PTS-Na) doped polypyrrole (S-PPy) polymer is designed to anchor discretionary mixtures of multiple metal cations, including iron (Fe<sup>3+</sup>), cobalt (Co<sup>3+</sup>), ruthenium (Ru<sup>3+</sup>), palladium (Pd<sup>2+</sup>), indium (In<sup>3+</sup>), iridium (Ir<sup>2+</sup>), and platinum (Pt<sup>2+</sup>) . As illustrated in Figure 1, the carbon surface can be tuned with different level of compositional complexities, including unary Pt<sub>1</sub>@NC, binary (MSAC-2, (PtFe)<sub>1</sub>@NC), ternary (MSAC-3, (PtFeIr)<sub>1</sub>@NC), quaternary (MSAC-4, (PtFeIrRu)<sub>1</sub>@NC), quinary (MSAC-5, (PtFeIrRuCo)<sub>1</sub>@NC), senary (MSAC-6, (PtFeIrRuCoPd)<sub>1</sub>@NC), and septenary (MSAC-7, (PtFeIrRuCoPdIn)<sub>1</sub>@NC) samples. The structural evolution of carbon surface dictates the activities of both ORR and HER. The senary MSAC-6 achieves the ORR mass activity of 18.1 A·mg<sub>metal</sub><sup>-1</sup> at 0.9 V (Vs reversible hydrogen electrode (RHE)) over 30K cycles, which is 164 times higher than that of commercial Pt/C. The quaternary MSAC-4 presented a comparable HER catalytic capability with that of Pt/C. These results indicate that the highly complexed carbon surface can enhance its ability over general electrochemical catalytic reactions. The mechanisms regarding of the ORR and HER activities of the alternated carbon surface are also theoretically and experimentally investigated in this work, showing that the synergistic effects amongst the co-doped atoms can activate or inactivate certain single-atom sites.</p>


Author(s):  
Jingwen Pan ◽  
Baoyu Gao ◽  
Pijun Duan ◽  
Kangying Guo ◽  
Muhammad Akram ◽  
...  

Nonradical pathway-based persulfate oxidation technology is considered to be a promising method for high-salinity organic wastewater treatment.


RSC Advances ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 87-113
Author(s):  
Rami J. Batrice ◽  
John C. Gordon

Solar energy has been used for decades for the direct production of electricity in various industries and devices. However, harnessing and storing this energy in the form of chemical bonds has emerged as a promising alternative to fossil fuels.


Author(s):  
Simran Kumari ◽  
Philippe Sautet

Supported single-atom and small cluster catalysts have become highly popular in heterogeneous catalysis. These catalysts can maximize the metal atom utilization while still showcasing superior catalytic performance. One of the...


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