an-atmospheric-pressure-plasma-setup-to-investigate-reactive-species

An Atmospheric Pressure Plasma Setup to Investigate the Reactive Species Formation

Non-thermal atmospheric pressure (&#39;cold&#39;) plasmas have received increased attention in recent years due to their significant biomedical potential. ...

University of York

The aerobic oxidation of 5-hydroxymethylfurfural, a versatile biomass-derived chemical, is examined in water with a titania-supported gold-nanoparticle catalyst at ambient temperature (30 °C). The selectivity of the reaction towards 2,5-furandicarboxylic acid and the intermediate oxidation product 5-hydroxymethyl-2-furancarboxylic acid is found to depend on the amount of added base and the oxygen pressure, suggesting that the reaction proceeds via initial oxidation of the aldehyde moiety followed by oxidation of the hydroxymethyl group of 5-hydroxymethylfurfural. Under optimized reaction conditions, a 71% yield of 2,5-furandicarboxylic acid is obtained at full 5-hydroxymethylfurfural conversion in the presence of excess base.

Gold-catalyzed aerobic oxidation of 5-hydroxymethylfurfural in water at ambient temperature.

The salts hexaaquamagnesium furan-2,5-dicarboxylate, [Mg(H(2)O)(6)](C(6)H(2)O(5)), (I), and hexaaquanickel furan-2,5-dicarboxylate, [Ni(H(2)O)(6)](C(6)H(2)O(5)), (II), provide the first crystallographic characterization of the furan-2,5-dicarboxylate dianion. Both structures exhibit extensive three-dimensional hydrogen-bonding networks between the octahedral coordinated hexaaquametal(II) ions and the dicarboxylate anions. Although the two structures are not isomorphous, they contain essentially identical two-dimensional slabs. The distinction between the structures is that these slabs are related by translation in (II), whereas adjacent slabs in (I) are reflected relative to each other by the action of a glide plane. The reflection occurs so that the local contacts between slabs are not changed, and thus the hydrogen-bond networks are identical except for the orientation of the water molecules at the interface between slabs.

Magnesium and nickel(II) furan-2,5-dicarboxylate.

Non-thermal atmospheric pressure plasma has attracted considerable attention in recent years due to its potential for biomedical applications. Determining the mechanism of the formation of reactive species in liquid treated with plasma is thus of paramount importance for both fundamental and applied research. In this work, the origin of reactive species in plasma-treated aqueous solutions was investigated by using spin-trapping, hydrogen and oxygen isotopic labelling and electron paramagnetic resonance (EPR) spectroscopy. The species originating from molecules in the liquid phase and those introduced with the feed gas were differentiated by EPR and (1) H NMR analysis of liquid samples. The effects of water vapour and oxygen admixtures in the feed gas were investigated. All the reactive species detected in the liquid samples were shown to be formed largely in the plasma gas phase. It is suggested that hydrogen peroxide (determined by UV/Vis analysis) is formed primarily in the plasma tube, whereas the radical species ⋅OOH, ⋅OH and ⋅H are proposed to originate from the region between the plasma nozzle and the liquid sample.

Yury Gorbanev

Department of Chemistry,
York Plasma Institute,
Department of Physics,
York Plasma Institute, Department of Physics

University of York

An Atmospheric Pressure Plasma Setup to Investigate the Reactive Species Formation

Yury Gorbanev

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Department of Chemistry,York Plasma Institute,Department of Physics,York Plasma Institute, Department of Physics

University of York

An Atmospheric Pressure Plasma Setup to Investigate the Reactive Species Formation

Department of Chemistry,
York Plasma Institute,
Department of Physics,
York Plasma Institute, Department of Physics