scholarly journals Interactions between atomically dispersed copper and phosphorous species are key for the hydrochlorination of acetylene

2022 ◽  
Vol 5 (1) ◽  
Author(s):  
Ting Wang ◽  
Zhao Jiang ◽  
Qi Tang ◽  
Bolin Wang ◽  
Saisai Wang ◽  
...  

AbstractVinyl chloride, the monomer of polyvinyl chloride (PVC), is industrially synthesized via acetylene hydrochlorination. Thereby, easy to sublimate but toxic mercury chloride catalysts are widely used. It is imperative to find environmentally friendly non-mercury catalysts to promote the green production of PVC. Low-cost copper-based catalysts are promising candidates. In this study, phosphorus-doped Cu-based catalysts are prepared. It is shown that the type of phosphorus configuration and the distribution on the surface of the carrier can be adjusted by changing the calcination temperature. Among the different phosphorus species, the formed P-C bond plays a key role. The coordination structure formed by the interaction between P-C bonds and atomically dispersed Cu2+ species results in effective and stable active sites. Insights on how P-C bonds activate the substrate may provide ideas for the design and optimization of phosphorus-doped catalysts for acetylene hydrochlorination.

2021 ◽  
Author(s):  
Ting Wang ◽  
Zhao Jiang ◽  
Qi Tang ◽  
Bolin Wang ◽  
Saisai Wang ◽  
...  

Abstract As an environmentally friendly non-mercury catalyst for the hydrochlorination of acetylene, Cu-based catalysts have always attracted attention. In this study, a series of phosphorus-doped Cu-based catalysts supported on activated carbon were prepared by the wet impregnation method, the difference of them is that the calcination temperature of phosphorus-doped carrier is 200 ℃, 400 ℃, 600 ℃ and 800 ℃ respectively. In the test conditions of T = 150℃, GHSV(C2H2) = 90 h− 1 and V(HCl): V(C2H2) = 1.2, the highest acetylene conversion was 83.1%. The type of phosphorus configuration and the distribution on the surface of the carrier can be adjusted by changing the calcination temperature. Among the different phosphorus species formed by the phosphorus doping treatment at different temperatures, the P-C bond formed after the phosphorus element is incorporated into the carbon lattice also accounts for an increasing proportion with the increase of the calcination temperature,which is accompanied by a higher and higher acetylene conversion. It can be seen that the P-C bond plays a key role in the acetylene hydrochlorination reaction in this system. Meanwhile, Cu2+ was identified as the main active component in the catalyst by XPS. The representative HAADF-STEM image shows isolated copper species, confirming that the single-center copper species supported on the carbon support is the active center of the acetylene hydrochlorination reaction. The coordination structure formed by the interaction between the P-C bond and the atomically dispersed Cu2+ species is an effective and stable active site in the reaction. Density functional theory calculations indicate that the reaction is proposed to proceed according to the Langmuir-Hinshelwood (L-H) mechanism. This work is the first to identify which phosphorus species plays a role in the hydrochlorination of acetylene, which may provide some ideas for the design and optimization of phosphorus doping catalysts in the future.


2019 ◽  
Vol 33 (05) ◽  
pp. 1950046
Author(s):  
Yuanyuan Zhang ◽  
Naibao Huang ◽  
Shaoming Qiao ◽  
Junjie Zhang ◽  
Zhengyuan Gao ◽  
...  

In order to reduce the cost of the catalysts for the anion exchange membrane fuel cell (AEMFC), phosphorus-doped XC-72 carbon catalyst was prepared by one-step carbonization using XC-72 carbon and triphenyl phosphorus (TPP) as carbon source and phosphorus source. The structure, morphology and electrochemical performance of the phosphorus-doped carbon catalyst were evaluated by physical characterization and electrochemical methods. When the proportion of triphenyl phosphorus and XC-72 is 1:5, and carbonization temperature is [Formula: see text], the obtained catalyst shows mesoporous structure formed by the accumulation of nanospheres and exhibits better electrochemical performance, including more positive onset potential (−0.12 V), the largest current density [Formula: see text], which is slightly equal to commercial 20%Pt/C [Formula: see text]. Moreover, P is doped in carbon with C–P and O–P bond, which provide active sites to improve electrochemical performance. Low cost precursor and facile preparation of P-doped C is a candidate for full cell catalyst.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Shan Wang ◽  
Aolin Lu ◽  
Chuan-Jian Zhong

AbstractAs a promising substitute for fossil fuels, hydrogen has emerged as a clean and renewable energy. A key challenge is the efficient production of hydrogen to meet the commercial-scale demand of hydrogen. Water splitting electrolysis is a promising pathway to achieve the efficient hydrogen production in terms of energy conversion and storage in which catalysis or electrocatalysis plays a critical role. The development of active, stable, and low-cost catalysts or electrocatalysts is an essential prerequisite for achieving the desired electrocatalytic hydrogen production from water splitting for practical use, which constitutes the central focus of this review. It will start with an introduction of the water splitting performance evaluation of various electrocatalysts in terms of activity, stability, and efficiency. This will be followed by outlining current knowledge on the two half-cell reactions, hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), in terms of reaction mechanisms in alkaline and acidic media. Recent advances in the design and preparation of nanostructured noble-metal and non-noble metal-based electrocatalysts will be discussed. New strategies and insights in exploring the synergistic structure, morphology, composition, and active sites of the nanostructured electrocatalysts for increasing the electrocatalytic activity and stability in HER and OER will be highlighted. Finally, future challenges and perspectives in the design of active and robust electrocatalysts for HER and OER towards efficient production of hydrogen from water splitting electrolysis will also be outlined.


2021 ◽  
Author(s):  
Song-Jeng Isaac Huang ◽  
Adil Muneeb ◽  
Sabhapathy Palani ◽  
Anjaiah Sheelam ◽  
Bayikadi Khasimsaheb ◽  
...  

Developing a non-precious metal electrocatalyst for oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) is desirable for low-cost energy conversion devices. Herein, we designed and developed a new class...


Vibration ◽  
2021 ◽  
Vol 4 (3) ◽  
pp. 551-584
Author(s):  
Samir Mustapha ◽  
Ye Lu ◽  
Ching-Tai Ng ◽  
Pawel Malinowski

The development of structural health monitoring (SHM) systems and their integration in actual structures has become a necessity as it can provide a robust and low-cost solution for monitoring the structural integrity of and the ability to predict the remaining life of structures. In this review, we aim at focusing on one of the important issues of SHM, the design, and implementation of sensor networks. Location and number of sensors, in any SHM system, are of high importance as they impact the system integration, system performance, and accuracy of assessment, as well as the total cost. Hence we are interested in shedding the light on the sensor networks as an essential component of SHM systems. The review discusses several important parameters including design and optimization of sensor networks, development of academic and commercial solutions, powering of sensors, data communication, data transmission, and analytics. Finally, we presented some successful case studies including the challenges and limitations associated with the sensor networks.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Guhankumar Ponnusamy ◽  
Hajar Farzaneh ◽  
Yongfeng Tong ◽  
Jenny Lawler ◽  
Zhaoyang Liu ◽  
...  

AbstractHeterogeneous catalytic ozonation is an effective approach to degrade refractory organic pollutants in water. However, ozonation catalysts with combined merits of high activity, good reusability and low cost for practical industrial applications are still rare. This study aims to develop an efficient, stable and economic ozonation catalyst for the degradation of Ibuprofen, a pharmaceutical compound frequently detected as a refractory pollutant in treated wastewaters. The novel three-dimensional network-structured catalyst, comprising of δ-MnO2 nanosheets grown on woven carbon microfibers (MnO2 nanosheets/carbon microfiber), was synthesized via a facile hydrothermal approach. Catalytic ozonation performance of Ibuprofen removal in water using the new catalyst proves a significant enhancement, where Ibuprofen removal efficiency of close to 90% was achieved with a catalyst loading of 1% (w/v). In contrast, conventional ozonation was only able to achieve 65% removal efficiency under the same operating condition. The enhanced performance with the new catalyst could be attributed to its significantly increased available surface active sites and improved mass transfer of reaction media, as a result of the special surface and structure properties of this new three-dimensional network-structured catalyst. Moreover, the new catalyst displays excellent stability and reusability for ibuprofen degradation over successive reaction cycles. The facile synthesis method and low-cost materials render the new catalyst high potential for industrial scaling up. With the combined advantages of high efficiency, high stability, and low cost, this study sheds new light for industrial applications of ozonation catalysts.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Gang Zhou ◽  
Peifang Wang ◽  
Hao Li ◽  
Bin Hu ◽  
Yan Sun ◽  
...  

AbstractOxygen evolution reaction (OER) plays a determining role in electrochemical energy conversion devices, but challenges remain due to the lack of effective low-cost electrocatalysts and insufficient understanding about sluggish reaction kinetics. Distinguish from complex nano-structuring, this work focuses on the spin-related charge transfer and orbital interaction between catalysts and intermediates to accelerate catalytic reaction kinetics. Herein, we propose a simple magnetic-stimulation approach to rearrange spin electron occupation in noble-metal-free metal-organic frameworks (MOFs) with a feature of thermal-differentiated superlattice, in which the localized magnetic heating in periodic spatial distribution makes the spin flip occur at particular active sites, demonstrating a spin-dependent reaction pathway. As a result, the spin-rearranged Co0.8Mn0.2 MOF displays mass activities of 3514.7 A gmetal−1 with an overpotential of ~0.27 V, which is 21.1 times that of pristine MOF. Our findings provide a new paradigm for designing spin electrocatalysis and steering reaction kinetics.


2017 ◽  
Vol 53 (86) ◽  
pp. 11733-11746 ◽  
Author(s):  
Grazia Malta ◽  
Simon J. Freakley ◽  
Simon A. Kondrat ◽  
Graham J. Hutchings

The replacement of mercuric chloride in the production of vinyl chloride monomer, a precursor to PVC, would greatly reduce the environmental impact of this large scale industrial process.


2016 ◽  
Vol 78 (8-3) ◽  
Author(s):  
Nurrulhidayah Salamun ◽  
Sugeng Triwahyono ◽  
Aishah Abdul Jalil

Mercury is one of the most toxic pollutants which pose a great threat to both human health and organism security. A great deal of research over recent decades has been motivated by the requirement to lower the concentration of these heavy metals in water and the need to develop low cost techniques which can be widely applied for heavy metals remediation. Adsorption is by far the most reliable technologies for removing mercury from water. In this study, banana stem fibers, a natural biomass was loaded with zirconium (IV) to investigate its feasibility for mercury removal from an aquatic environment. The XRD pattern for both BSF-HCl and Zr/BSF-HCl exhibited mainly the cellulose I structure which consists of two distinct crystal phases. The FESEM images illustrated the presence of relatively well organized, pronounced and uniform cavities distributed around the surface, indicated a good possibility for the metal ions to be adsorbed. The result shows that Hg (II) adsorption capacity increased from 45 to 72 mg/g after the immobilization of Zr due to increase in the active sites on the adsorbent. 


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