Ion-selective electrode and enzyme sensors for flow-type environmental analysis

1991 ◽  
Vol 56 (1) ◽  
pp. 178-191 ◽  
Author(s):  
J. D. R. Thomas
Keyword(s):  
Hydrogen Peroxide ◽  
Metal Oxide ◽  
Environmental Analysis ◽  
Lead Dioxide ◽  
Membrane System ◽  
Electrochemical Analysis ◽  
Oxide Catalysts ◽  
Metal Oxide Catalysts ◽  
Catalytic Membrane ◽  
Wide Range

Illustrative examples from researches in the author’s laboratories are given of potentiometric ion-selective electrodes (ISEs) and catalytic membrane amperometric electrodes suitable for environmental analysis. The uses of sulphide ISEs are demonstrated for monitoring the activities of sulphate-reducing bacteria, in effluent analysis for sulphide, and in process/effluent analysis for sulphide, thiols and polysulphides. Diquat and paraquat ISEs are discussed in relation to their optimisation in terms of appropriate crown ether and ion-pairing agents, together with prospects of their uses. Catalytic membrane systems for use in electrochemical analysis may be based on metal oxide catalysts or enzymes. The best of the new metal oxide catalysts for hydrogen peroxide analysis in association with an oxygen electrode is based on manganese dioxide and offers an alternative to lead dioxide and catalase. An alternative membrane system for use with a platinum electrode is peroxidase in association with a mediator in order to permit a low potential approach for hydrogen peroxide sensing. Hydrogen peroxide is a product of many oxidase catalysed reactions and its electrochemical detection permits the analysis of a wide range of substrates, illustrated here for glucose in various food products and hypoxanthine in the spoilage of fish meats.

Unravelling the cooperative role of lattice strain on MnO2/TiO2 and MnO2/ZnO catalysts for fast decomposition of hydrogen peroxide

2021 ◽  
Author(s):  
Santhanaraj Daniel ◽  
Selvamani Arumugam ◽  
RajaKumar KANTHAPAZHAM ◽  
Ricky Joseph Nicholson ◽  
Giridhar Sridhar ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Metal Oxide ◽  
Dft Calculations ◽  
Lattice Strain ◽  
Experimental Methods ◽  
Oxide Catalysts ◽  
Metal Oxide Catalysts ◽  
Fast Decomposition

The influence of lattice strain on metal and metal oxide catalysts has been widely investigated by DFT calculations. However, it is still hard to prove by experimental methods. In the...

scholarly journals Vapor-phase Stabilization of Biomass Pyrolysis Vapors Using Mixed-metal Oxide Catalysts

2019 ◽  
Author(s):  
Charles W. Edmunds ◽  
Calvin Mukarakate ◽  
Mengze Xu ◽  
Yagya N. Regmi ◽  
Choo Hamilton ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Oxide Catalysts ◽  
Ex Situ ◽  
Mixed Metal Oxide ◽  
Successful Implementation ◽  
Metal Oxide Catalysts ◽  
Biomass Pyrolysis ◽  
Mixed Metal ◽  
Wide Range ◽  
Mixed Metal Oxide Catalysts

<div>Mixed-metal oxides possess a wide range of tunability and show promise for catalytic stabilization of biomass pyrolysis products. For materials derived from layered double hydroxides, understanding the effect of divalent cation species and divalent/trivalent cation stoichiometric ratio on catalytic behavior is critical to their successful implementation. In this study, four mixed-metal oxide catalysts consisting of Al, Zn, and Mg in different stoichiometric ratios were synthesized and tested for ex-situ catalytic fast pyrolysis (CFP) using pine wood as feedstock. The catalytic activity and deactivation behavior of these catalysts were monitored in real-time using a lab-scale pyrolysis reactor and fixed catalyst bed coupled with a molecular beam mass spectrometer (MBMS), and data were analyzed by multivariate statistical approaches. In comparing Mg- and Zn-Al catalyst materials, we demonstrate that the Mg-Al materials possessed greater quantities of basic sites, which we attribute to their higher surface areas, and they produced upgraded pyrolysis vapors which contained less acids and more deoxygenated aromatic hydrocarbons such as toluene and xylene. However, detrimental impacts on carbon yields were realized via decarbonylation and decarboxylation reactions and coke formation. Given that the primary goals of catalytic upgrading of bio-oil are deoxygenation, reduction of acidity, and high carbon yield, these results highlight both promising catalytic effects of mixed-metal oxide materials and opportunities for improvement.</div>

scholarly journals Vapor-phase Stabilization of Biomass Pyrolysis Vapors Using Mixed-metal Oxide Catalysts

2018 ◽  
Author(s):  
Charles W. Edmunds ◽  
Calvin Mukarakate ◽  
Mengze Xu ◽  
Yagya N. Regmi ◽  
Choo Hamilton ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Oxide Catalysts ◽  
Ex Situ ◽  
Mixed Metal Oxide ◽  
Successful Implementation ◽  
Metal Oxide Catalysts ◽  
Biomass Pyrolysis ◽  
Mixed Metal ◽  
Wide Range ◽  
Mixed Metal Oxide Catalysts

<div>Mixed-metal oxides possess a wide range of tunability and show promise for catalytic stabilization of biomass pyrolysis products. For materials derived from layered double hydroxides, understanding the effect of divalent cation species and divalent/trivalent cation stoichiometric ratio on catalytic behavior is critical to their successful implementation. In this study, four mixed-metal oxide catalysts consisting of Al, Zn, and Mg in different stoichiometric ratios were synthesized and tested for ex-situ catalytic fast pyrolysis (CFP) using pine wood as feedstock. The catalytic activity and deactivation behavior of these catalysts were monitored in real-time using a lab-scale pyrolysis reactor and fixed catalyst bed coupled with a molecular beam mass spectrometer (MBMS), and data were analyzed by multivariate statistical approaches. In comparing Mg- and Zn-Al catalyst materials, we demonstrate that the Mg-Al materials possessed greater quantities of basic sites, which we attribute to their higher surface areas, and they produced upgraded pyrolysis vapors which contained less acids and more deoxygenated aromatic hydrocarbons such as toluene and xylene. However, detrimental impacts on carbon yields were realized via decarbonylation and decarboxylation reactions and coke formation. Given that the primary goals of catalytic upgrading of bio-oil are deoxygenation, reduction of acidity, and high carbon yield, these results highlight both promising catalytic effects of mixed-metal oxide materials and opportunities for improvement.</div>

The oxidation of olefins by t-butyl hydrogen peroxide to prepare 1,2-diols over metal oxide catalysts

2009 ◽  
Vol 10 (9) ◽  
pp. 1279-1283 ◽  
Author(s):  
Qi Neng Zhang ◽  
Jing Zhang ◽  
Ting Hua Wu ◽  
Xiao Ping Zhou
Keyword(s):  
Hydrogen Peroxide ◽  
Metal Oxide ◽  
Oxide Catalysts ◽  
Metal Oxide Catalysts ◽  
Oxidation Of Olefins

scholarly journals Vapor-phase Stabilization of Biomass Pyrolysis Vapors Using Mixed-metal Oxide Catalysts

2019 ◽  
Author(s):  
Charles W. Edmunds ◽  
Calvin Mukarakate ◽  
Mengze Xu ◽  
Yagya N. Regmi ◽  
Choo Hamilton ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Oxide Catalysts ◽  
Ex Situ ◽  
Mixed Metal Oxide ◽  
Successful Implementation ◽  
Metal Oxide Catalysts ◽  
Biomass Pyrolysis ◽  
Mixed Metal ◽  
Wide Range ◽  
Mixed Metal Oxide Catalysts

<div>Mixed-metal oxides possess a wide range of tunability and show promise for catalytic stabilization of biomass pyrolysis products. For materials derived from layered double hydroxides, understanding the effect of divalent cation species and divalent/trivalent cation stoichiometric ratio on catalytic behavior is critical to their successful implementation. In this study, four mixed-metal oxide catalysts consisting of Al, Zn, and Mg in different stoichiometric ratios were synthesized and tested for ex-situ catalytic fast pyrolysis (CFP) using pine wood as feedstock. The catalytic activity and deactivation behavior of these catalysts were monitored in real-time using a lab-scale pyrolysis reactor and fixed catalyst bed coupled with a molecular beam mass spectrometer (MBMS), and data were analyzed by multivariate statistical approaches. In comparing Mg- and Zn-Al catalyst materials, we demonstrate that the Mg-Al materials possessed greater quantities of basic sites, which we attribute to their higher surface areas, and they produced upgraded pyrolysis vapors which contained less acids and more deoxygenated aromatic hydrocarbons such as toluene and xylene. However, detrimental impacts on carbon yields were realized via decarbonylation and decarboxylation reactions and coke formation. Given that the primary goals of catalytic upgrading of bio-oil are deoxygenation, reduction of acidity, and high carbon yield, these results highlight both promising catalytic effects of mixed-metal oxide materials and opportunities for improvement.</div>

Consequences of Confinement for Alkene Epoxidation with Hydrogen Peroxide on Highly Dispersed Group 4 and 5 Metal Oxide Catalysts

ACS Catalysis ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 2995-3010 ◽  
Author(s):  
Daniel T. Bregante ◽  
Nicholas E. Thornburg ◽  
Justin M. Notestein ◽  
David W. Flaherty
Keyword(s):  
Hydrogen Peroxide ◽  
Metal Oxide ◽  
Oxide Catalysts ◽  
Metal Oxide Catalysts ◽  
Group 4 ◽  
Highly Dispersed
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