Highly active and stable bimetallic Au-Pd catalysts have been extensively studied for several liquid-phase oxidation reactions in recent years, but there are far fewer reports on the use of these catalysts for low-temperature gas-phase reactions. Here we initially established the presence of a synergistic effect in a range of bimetallic Au-Pd/CeZrO4 catalysts, by measuring their activity for se...

A gas-phase oxidation method using dielectric barrier discharges (DBDs) has been developed to remove S02 and to simultaneously remove SO, and NO from gas streams that are similar to gas streams generated by the combustion of fossil fuels. SO, and NO removal efficiencies are evaluated as a function of applied voltage, temperature, and concentrations of S02, NO, t'l,O~s), and N H 3. With constant...

Corrosion of iron and mild steel in gas environments at 550 °C was studied by Gas Phase Analysis (GPA) using 13C16,16O2 18,18O2. This technique is shown to be very powerful identifying gas–metal gas-gas interactions. Mild reacts with O2 oxidize decarburise, CO2 decarburise but not oxidize, CO2/O2 carburise. Using simple kinetic modeling, it demonstrated that the oxidation rate initially control...

In studies on endogenous plant gibberellins (GAs), reverse phase (Bondapak C(18)) high performance liquid chromatography (HPLC) has proved to be a useful method for the fractionation of plant extracts. The behavior of 18 authentic GAs in such a chromatographic system is described. The main factors determining chromatographic behavior are the degree and the position of hydroxylation of the GA. G...

Temperature-dependent rf-ion trap mass spectrometry and first-principles simulations reveal the detailed reaction mechanism of the catalytic gas-phase oxidation of CO by free Au(2)(-) ions in the presence of O(2). A metastable intermediate with a mass of Au(2)CO(3)(-) was observed at low temperatures. Two alternative structures corresponding to digold carbonate or peroxyformate are predicted fo...

Organic compounds emitted in the atmosphere are oxidized in complex reaction sequences that produce a myriad of intermediates. Although the cumulative importance of these organic intermediates is widely acknowledged, there is still a critical lack of information concerning the detailed composition of the highly functionalized secondary organics in the gas and condensed phases. The evaluation of...

Four Mo-based catalysts were prepared via three different synthesis techniques supported on SiO2 and/or SBA-15. By means of complementary in situ characterization techniques, the carburization process and final characteristics these investigated. Additionally, four evaluated for activation CO2 absence presence H2 (reverse water–gas shift, RWGS). The results suggest that reacts a dissociation ca...

Our current understanding of secondary organic aerosol (SOA) formation is limited by our knowledge of gaseous secondary organics involved in gas/particle partitioning. The objective of this study is to explore (i) the potential for products of multiple oxidation steps contributing to SOA, and (ii) the evolution of the SOA/VOC/NOx system. We developed an explicit model based on the coupling of d...

High-concentration CaO particles and gas compositions have a significant influence on NOx reduction by selective non-catalytic reduction (SNCR) in cement precalciners. The effect of gas composition on NOx reduction by SNCR with NH₃ was studied in a cement precalciner atmosphere with and without CaO at 700-1100 °C. It was found that CaO significantly lowers NOx reduction efficiency between 750 °...

In atmospheric conditions the oxidation of sulphur dioxide to sulphuric acid in gas phase has been considered to be determined by the concentration of hydroxyl radical. Recently the significance of stabilized Criegee intermediate as an oxidizer of sulphuric acid has been brought out. In this study we investigated the oxidation of sulphur dioxide in the CLOUD chamber in conditions where the hydr...