Removing Surface Hydroxyl Groups of Ce-Modified MnO2 To Significantly Improve Its Stability for Gaseous Ozone Decomposition

2017 ◽  
Vol 121 (42) ◽  
pp. 23488-23497 ◽  
Author(s):  
Yang Liu ◽  
Pengyi Zhang
Keyword(s):  
Hydroxyl Groups ◽  
Ozone Decomposition ◽  
Surface Hydroxyl ◽  
Surface Hydroxyl Groups ◽  
Gaseous Ozone

scholarly journals The behavior of ozone on different iron oxides surface sites in water

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Liqiang Yan ◽  
Jishuai Bing ◽  
Hecheng Wu
Keyword(s):  
Iron Oxides ◽  
Lewis Acid ◽  
Acid Sites ◽  
Oh Radicals ◽  
Hydroxyl Groups ◽  
Ozone Decomposition ◽  
Lewis Acid Sites ◽  
Surface Hydroxyl ◽  
Surface Hydroxyl Groups ◽  
Surface Metal

Abstract A transformation process of ozone on different iron oxides suspensions, including α-Fe2O3, α-FeOOH, Fe3O4, was carried out using FTIR of adsorbed pyridine, ATR-FTIR and electron paramagnetic resonance (EPR) spectra with isotope 18O3. It was verified that on the surface isolated hydroxyl groups and the surface hydroxyl groups without acid sites of these iron oxides, ozone was electrostatically adsorbed and did not interact with the surface of these oxides, stably existed as ozone molecule. In contrast, ozone could replace the surface hydroxyl groups on Lewis acid sites of oxides, and directly interacted with the surface metal ions, decomposing into reactive oxygen species (ROS) and initiating the surface metal redox. The results indicate that Lewis acid sites were active center while the electronic cycle of the Fe2+/Fe3+ is advantageous to promote ozone decomposition into O2•− and •OH radicals. The mechanism of catalytic ozonation in different surface acid sites of iron oxides aqueous suspension was proposed on the basis of all experimental information.

Catalytic ozonation of p-chloronitrobenzene over pumice-supported zinc oxyhydroxide

2013 ◽  
Vol 68 (8) ◽  
pp. 1895-1900 ◽  
Author(s):  
Lei Yuan ◽  
Jimin Shen ◽  
Zhonglin Chen
Keyword(s):  
Hydroxyl Radicals ◽  
Underlying Mechanism ◽  
Catalytic Ozonation ◽  
Point Of Zero Charge ◽  
Hydroxyl Groups ◽  
Ozone Decomposition ◽  
Surface Hydroxyl ◽  
Heterogeneous Catalytic ◽  
Surface Hydroxyl Groups ◽  
Catalytic Ozone

The catalytic ozonation of p-chloronitrobenzene (pCNB) in an aqueous solution using pumice-supported zinc oxyhydroxide (ZMP) as the catalyst was investigated. ZMP significantly enhanced the degradation efficiency in the heterogeneous catalytic ozonation compared with ozonation alone. The decomposition rate of the aqueous ozone increased 2.84-fold in the presence of ZMP. Catalytic ozone decomposition showed that pCNB is oxidized primarily by hydroxyl radicals (•OH) in ozonation/ZMP processes. This modification increases the density of surface hydroxyl groups as well as the pH at the point of zero charge (pHPZC) of pumice, resulting in the appearance of new ZnO and Zn(OH)2 crystalline phases. An investigation of the underlying mechanism confirms that ZnOOH loading promotes •OH initiation, which enhances the degradation of pCNB.

The synthesis and structure of silica-supported bis(h5-cyclopentadienyl)dichlorotitanium(IV) complexes

1986 ◽  
Vol 51 (7) ◽  
pp. 1430-1438 ◽  
Author(s):  
Alena Reissová ◽  
Zdeněk Bastl ◽  
Martin Čapka
Keyword(s):  
Free Surface ◽  
Hydroxyl Groups ◽  
Titanium Complex ◽  
Surface Hydroxyl ◽  
Surface Hydroxyl Groups ◽  
Free Hydroxyl ◽  
Cyclopentadienyl Anion

The title complexes have been obtained by functionalization of silica with cyclopentadienylsilanes of the type Rx(CH3)3 - xSi(CH2)nC5H5 (x = 1-3, n = 0, 1, 3), trimethylsilylation of free surface hydroxyl groups, transformation of the bonded cyclopentadienyl group to the cyclopentadienyl anion, followed by coordination of (h5-cyclopentadienyl)trichlorotitanium. The effects of single steps of the above immobilization on texture of the support, the number of free hydroxyl groups, the coverage of the surface by cyclopentadienyl groups and the degree of their utilization in anchoring the titanium complex have been investigated. ESCA study has shown that the above anchoring leads to formation of the silica-supported bis(h5-cyclopentadienyl)dichlorotitanium(IV) complex.

Controllable synthesis of phosphate-modified BiPO4 nanorods with high photocatalytic activity: surface hydroxyl groups concentrations effects

RSC Advances ◽  
2015 ◽  
Vol 5 (121) ◽  
pp. 99712-99721 ◽  
Author(s):  
Yan Li ◽  
Yawen Wang ◽  
Yu Huang ◽  
Junji Cao ◽  
Wingkei Ho ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Surface Modification ◽  
Photocatalytic Performance ◽  
High Photocatalytic Activity ◽  
Hydroxyl Groups ◽  
Controllable Synthesis ◽  
Surface Hydroxyl ◽  
Methylene Orange ◽  
Surface Hydroxyl Groups

Surface modification by phosphate efficiently improves the photocatalytic performance of BiPO4 for the degradation of methylene orange (MO), by enhancing the concentration of surface hydroxyl groups and improving its hydrophilicity.

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