Heterogeneous Catalytic Reduction for Water Purification: Nanoscale Effects on Catalytic Activity, Selectivity, and Sustainability

Some physical and catalytic properties of the two-component copper(II)oxide-chromium(III)oxide catalyst with different content of both components were studied using the decomposition of the aqueous solution of hydrogen peroxide as a testing reaction. It has been found that along to both basic components, the system under study contains also the spinel structure CuCr2O4, chromate washable by water and hexavalent ions of chromium unwashable by water. The soluble chromate is catalytically active. During the first period of the reaction the equilibrium is being established in both homogeneous and heterogeneous catalytic systems. The catalytic activity as well as the specific surface area of the washed solid is a non-monotonous function of its composition. It seems highly probable that the extreme values of both these quantities are not connected with the detected admixtures in the catalytic system. The system under study is very insensitive with regard to the applied doses of gamma radiation. Its catalytic properties are changed rather significantly after the thermal treatment and particularly after the partial reduction to low degree by hydrogen. The observed changes of the catalytic activity of the system under study are very probably in connection with the changes of the valence state of the catalytically active components of the catalyst.

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Reactive Oxygen Species and Catalytic Active Sites in Heterogeneous Catalytic Ozonation for Water Purification

Environmental Science & Technology ◽

10.1021/acs.est.0c00575 ◽

2020 ◽

Vol 54 (10) ◽

pp. 5931-5946 ◽

Cited By ~ 10

Author(s):

Guangfei Yu ◽

Yuxian Wang ◽

Hongbin Cao ◽

He Zhao ◽

Yongbing Xie

Keyword(s):

Reactive Oxygen Species ◽

Water Purification ◽

Active Sites ◽

Reactive Oxygen ◽

Catalytic Ozonation ◽

Oxygen Species ◽

Heterogeneous Catalytic ◽

Catalytic Active Sites

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A Review on the Catalytic Hydrogenation of Bromate in Water Phase

Catalysts ◽

10.3390/catal11030365 ◽

2021 ◽

Vol 11 (3) ◽

pp. 365

Author(s):

Jose Luis Cerrillo ◽

Antonio Eduardo Palomares

Keyword(s):

Catalytic Activity ◽

Ion Exchange ◽

Reaction Mechanisms ◽

Catalytic Reduction ◽

Environmental Concern ◽

Chemical Reduction ◽

Catalyst Stability ◽

Polluted Water ◽

Water Composition

The presence of bromate in water sources generates environmental concern due to its toxicity for humans. Diverse technologies, like membranes, ion exchange, chemical reduction, etc., can be employed to treat bromate-polluted water but they produce waste that must be treated. An alternative to these technologies can be the catalytic reduction of bromate to bromide using hydrogen as a reducing agent. In this review, we analyze the research published about this catalytic technology. Specifically, we summarize and discuss about the state of knowledge related to (1) the different metals used as catalysts for the reaction; (2) the influence of the support on the catalytic activity; (3) the characterization of the catalysts; (4) the reaction mechanisms; and (5) the influence of the water composition in the catalytic activity and in the catalyst stability. Based on published papers, we analyze the strength and weaknesses of this technique and the possibilities of using this reaction for the treatment of bromate-polluted water as a sustainable process.

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Construction of solvent-dependent self-assembled porous Ni(ii)-coordinated frameworks as effective catalysts for chemical transformation of CO2

RSC Advances ◽

10.1039/c6ra22971a ◽

2016 ◽

Vol 6 (109) ◽

pp. 108010-108016 ◽

Cited By ~ 3

Author(s):

Zhen Zhou ◽

Lu Yang ◽

Yefei Wang ◽

Cheng He ◽

Tao Liu ◽

...

Keyword(s):

Catalytic Activity ◽

Chemical Transformation ◽

Self Assembly ◽

Ambient Conditions ◽

Heterogeneous Catalytic ◽

Self Assembled

Two types of Ni(ii)-based coordinated frameworks have been solvothermally synthesized via solvent driven self-assembly, showing efficient heterogeneous catalytic activity toward cycloaddition of CO2 with epoxides under ambient conditions.

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Microstructure of Porous V2O-CeO2-SiO2 Catalyst for SCR of NO with NH3 at Low Temperature

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.875-877.213 ◽

2014 ◽

Vol 875-877 ◽

pp. 213-217 ◽

Cited By ~ 1

Author(s):

Mohd Razali Sohot ◽

Umi Sarah Jais ◽

Muhd Rosli Sulaiman

Keyword(s):

Catalytic Activity ◽

Low Temperature ◽

Catalytic Reduction ◽

Sol Gel ◽

Reduction Process ◽

No Emission ◽

Scr Of No ◽

Before And After ◽

The Right ◽

Proven Method

Selective catalytic reduction (SCR) is a well-proven method to reduce NO emission. However, to choose the right catalyst that provides a surface for reaction between NO and ammonia at low temperatures is a challenging task for a catalysts developers. In an earlier study, we prepared V2O5-CeO2-SiO2 catalyst with increasing V2O5 content by sol-gel route and found that the catalytic activity improved with increasing the V2O5 loading up to 0.5%. The catalytic activity, however, dropped when V2O5 loading was about 1% and increased back when the loading of V2O5 was about 5%. In this study, we looked into the microstructural relationship to explain these findings. The microstructures of the catalysts before and after exposure to NO gas revealed that the catalysts with 0.2% and 0.5% V2O5 were more porous after the reduction process possibly due to improved breakdown of (NH4)HCO3 to NH3 by the possible interaction with the V2O5 and CeO2-containing catalysts which consequently resulted in a more efficient NO reduction to N2 and H2O at low temperature. The microstructure of the catalyst with 1% V2O5 content to 5%, improved back the efficiency although clogging by CeVO4 phase still possible due to its presence based on XRD. The well-ordered micropores before exposure to NO and the more efficient breakdown of (NH4)HCO3 could have contributed to increase back the catalytic activity at low temperature.

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