Incorporation of Cu(ii) and its selective reduction to Cu(i) within confined spaces: efficient active sites for CO adsorption

2018 ◽  
Vol 6 (19) ◽  
pp. 8930-8939 ◽  
Author(s):  
Yu-Xia Li ◽  
Shuai-Shuai Li ◽  
Ding-Ming Xue ◽  
Xiao-Qin Liu ◽  
Meng-Meng Jin ◽  
...  
Keyword(s):  
Active Sites ◽  
Co Adsorption ◽  
Selective Reduction ◽  
Confined Spaces ◽  
Adsorption Performance

A two-step double-solvent strategy was first used to incorporate Cu(i) sites into MIL-101(Cr), which obviously improves the CO adsorption performance.

scholarly journals Bifunctional Materials for CO₂ Adsorption: Short Review

2021 ◽  
Vol 7 (2) ◽  
pp. 15-19
Author(s):  
S. M. Yusof ◽  
L. P. Teh
Keyword(s):  
Surface Area ◽  
Active Sites ◽  
Co2 Adsorption ◽  
High Surface ◽  
Co Adsorption ◽  
High Surface Area ◽  
Short Review ◽  
High Dispersion ◽  
High Porosity ◽  
Adsorption Performance

In recent years, there has been growing interest in adsorbents with high surface area, high porosity, high stability and high selectivity for CO2 adsorption. By the incorporation of the additive on the supports such as zeolite, silica, and carbon, the physicochemical properties of the adsorbent and CO2 adsorption performance can be enhanced. In this review, we focus on the overview of bifunctional materials (BFMs) for CO2 adsorption. The findings of this study suggests that the high surface area and high porosity of the support provide a good medium for high dispersion and accessibility of additives (amine or metal oxide), enhancing the CO2 adsorption efficiency. The excessive additive however may lead to a decrease of CO2 adsorption performance due to pore blockage and the decrease of active sites for CO2 interactions. The synergistic relationship of the supporting material and additive is significant towards the enhancement of CO2 adsorption.

Controlled Construction of Cu(I) Sites within Confined Spaces via Host–Guest Redox: Highly Efficient Adsorbents for Selective CO Adsorption

2018 ◽  
Vol 10 (46) ◽  
pp. 40044-40053 ◽  
Author(s):  
Yu-Xia Li ◽  
Yu-Nong Ji ◽  
Meng-Meng Jin ◽  
Shi-Chao Qi ◽  
Shuai-Shuai Li ◽  
...  
Keyword(s):  
Co Adsorption ◽  
Confined Spaces ◽  
Highly Efficient

Selective Reduction of NOxwith Propene under Oxidative Conditions:  Nature of the Active Sites on Copper-Based Catalysts

1997 ◽  
Vol 119 (12) ◽  
pp. 2905-2914 ◽  
Author(s):  
C. Márquez-Alvarez ◽  
I. Rodríguez-Ramos ◽  
A. Guerrero-Ruiz ◽  
G. L. Haller ◽  
M. Fernández-García
Keyword(s):  
Active Sites ◽  
Selective Reduction

Silver-alumina catalysts for selective reduction of NO by higher hydrocarbons: structure of active sites and reaction mechanism

2001 ◽  
Vol 30 (1-2) ◽  
pp. 151-162 ◽  
Author(s):  
Ken-ichi Shimizu ◽  
Junji Shibata ◽  
Hisao Yoshida ◽  
Atsushi Satsuma ◽  
Tadashi Hattori
Keyword(s):  
Reaction Mechanism ◽  
Active Sites ◽  
Selective Reduction ◽  
Reduction Of No ◽  
Higher Hydrocarbons ◽  
Alumina Catalysts

Active sites and states in the heterogeneous catalysis of carbon–hydrogen bonds

2005 ◽  
Vol 363 (1829) ◽  
pp. 879-900 ◽  
Author(s):  
Gabor A Somorjai ◽  
Anderson L Marsh
Keyword(s):  
Surface Structure ◽  
Active Sites ◽  
High Pressures ◽  
Bond Activation ◽  
Co Adsorption ◽  
Molecular Rearrangement ◽  
Platinum Surface ◽  
Bond Dissociation ◽  
Surface Mobility ◽  
Structure Sensitive

C–H bond activation for several alkenes (ethylene, propylene, isobutene, cyclohexene and 1-hexene) and alkanes (methane, ethane, n -hexane, 2-methylpentane and 3-methylpentane) has been studied on the (111) crystal face of platinum as a function of temperature at low (<10 −6  Torr) and high (≥1 Torr) pressures in the absence and presence of hydrogen pressures (≥10 Torr). Sum frequency generation (SFG) vibrational spectroscopy has been used to characterize the adsorbate structures and high pressure scanning tunnelling microscopy (HP-STM) has been used to monitor their surface mobility under reaction conditions during hydrogenation, dehydrogenation and CO poisoning. C–H bond dissociation occurs at low temperatures, approximately 250 K, for all of these molecules, although only at high pressures for the weakly bound alkanes because of their low desorption temperatures. Bond dissociation is known to be surface structure sensitive and we find that it is also accompanied by the restructuring of the metal surface. The presence of hydrogen slows down dehydrogenation and for some of the molecules it influences the molecular rearrangement, thus altering reaction selectivity. Surface mobility of adsorbates is essential to produce catalytic activity. When surface diffusion is inhibited by CO adsorption, ordered surface structures form and the reaction is poisoned. Ethylene hydrogenation is surface structure insensitive, while cyclohexene hydrogenation and dehydrogenation are structure sensitive. n -Hexane and other C 6 alkanes form either upright or flat-lying molecules on the platinum surface which react to produce branched isomers or benzene, respectively.

Study on Mercury Adsorption Performance of Modified Fly Ash

2011 ◽  
Vol 343-344 ◽  
pp. 246-249 ◽  
Author(s):  
Ting Yu Zhu ◽  
Jun Yan Kuang ◽  
Wen Qing Xu ◽  
Meng Ye ◽  
Yang Yang Guo ◽  
...  
Keyword(s):  
Fly Ash ◽  
Pore Structure ◽  
Active Sites ◽  
Chemical Adsorption ◽  
Mercury Adsorption ◽  
Adsorption Performance ◽  
Removal Efficiencies ◽  
Modified Fly Ash

The fly ash was modified by Cl, Fe, Cu salts to investigate the mercury adsorption performance and analyze the impacts on it. Experiment results indicate that significant improvement of removal efficiencies with FeCl3、CuCl2 and CuBr2 impregnation onto fly ash. The modification adjusted the pore structure of fly ash and formed more pores to absorb Hg, also it was found that new active sites were generated after the treatment, which can oxidize Hg0 and improve chemical adsorption.

Influence of the preparation method on the selective reduction of nitric oxide over Cu-ZSM-5. Nature of the active sites

1994 ◽  
Vol 4 (2-3) ◽  
pp. 199-211 ◽  
Author(s):  
Zakaria Chajar ◽  
Michel Primet ◽  
Hélène Praliaud ◽  
Miche`le Chevrier ◽  
Catherine Gauthier ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Active Sites ◽  
Preparation Method ◽  
Selective Reduction

scholarly journals The green, ultrafine cellulose-based porous nanofibrous membranes for efficient heavy metal ion removal through incorporation of chitosan by various electrospinning ways

2022 ◽  
Author(s):  
Qiushi Li ◽  
Ganmao Su ◽  
Ronggang Luo ◽  
Guanben Du ◽  
Linkun Xie ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Active Sites ◽  
Metal Removal ◽  
Copper Ions ◽  
Core Shell ◽  
Adsorption Effect ◽  
Adsorption Sites ◽  
Adsorption Performance ◽  
The Core ◽  
Nanofibrous Membranes

Abstract The rapid global industrialization worsens the contamination of heavy metals in aquatic ecosystems on the earth. In this study, the green, ultrafine cellulose-based porous nanofibrous membranes for efficient heavy metal removal through incorporation of chitosan by the conventional and core-shell electrospinning ways were firstly obtained. The relations among parameters of electrospun solution, micro-morphology and porosity for nanofibers, the variation of chemical active sites and adsorption performance of biocomposite nanofibrous membranes for conventional and core-shell electrospinning as well as the adsorption effect factors of copper ions including initial concentration, pH of solution and interaction time were comprehensively investigated. The results show that the average diameter for conventional and core-shell ultrafine nanofibers at 50% chitosan and 30% chitosan loading can achieve 56.22 nm and 37.28 nm, respectively. The core-shell cellulose acetate/chitosan (CA/CS) biocomposite nanofibrous membranes induced the surface aggregation of copper ions to impede the further adsorption. The more uniform distribution for chemical adsorption sites can be obtained by the conventional single-nozzle electrospinning than by the core-shell one, which promotes the adsorption performance of copper ions and decreases the surface shrinkage of nanofibrous membranes during adsorption. The 30% CS conventional nanofibrous membranes at the pH=5 aqueous solution showed the optimum adsorption capacity of copper ions (86.4 mg/g). The smart combination of renewable biomass with effective chemical adsorptive sites, the electrospinning technology with interwoven porous structure and the adsorption method with low cost and facile operation shows a promising prospect for water treatment.

scholarly journals High CO Adsorption Performance of CuCl-Modified Diatomites by Using the Novel Method “Atomic Implantation”

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Manh B. Nguyen ◽  
Tuyen V. Nguyen ◽  
Giang H. Le ◽  
Trang T. T. Pham ◽  
Khu Le Van ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Co Adsorption ◽  
The Novel ◽  
Freundlich Model ◽  
Adsorption Performance ◽  
Highly Dispersed ◽  
Novel Method ◽  
Implantation Method

An atomic implantation method was used to modify diatomite with CuCl. The CuCl/diatomite samples were characterized by different techniques, including FTIR, XRD, BET, SEM-TEM, EDX, and CO-TPR. Characterization results revealed the formation of CuCl particles of 50–60 nm highly dispersed on diatomite surface. CO adsorption measurements showed that 2CuCl/diatomite exhibits the highest CO adsorption capacity among all CuCl-modified samples with diatomite. Its CO adsorption capacity of 2.96 mmol/g at 30°C is 10 times higher than that of unmodified diatomite (0.29 mmol/g). The CO adsorption on CuCl-modified diatomites was found to fit well with the Langmuir–Freundlich model.

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