Sulfate particles play a key role in the air quality and the global climate, but the heterogeneous formation mechanism of sulfates on surfaces of atmospheric particles is not well established. Carbonates, which act as a reactive component in mineral dust due to their special chemical properties, may contribute significantly to the sulfate formation by heterogeneous processes. This paper present...

Carbon-enriched coal fly ash was evaluated in this work as a low-cost adsorbent for SO2 removal from stack gases. The unburned carbon in coal fly ash was concentrated by mechanical sieving and vegetal oil agglomeration. The carbon concentrates were activated with steam at 900 degrees C in order to develop porosity onto the samples. The performance of these samples in the SO2 abatement was teste...

The gas-sensing properties of Pt-decorated carbon nanotubes (CNTs), which provide a foundation for the fabrication of sensors, have been evaluated. In this study, we calculated the gas adsorption of Pt-decorated (8,0) single-wall CNTs (Pt-SWCNTs) with SO2, H2S, and CO using GGA/PW91 method based on density functional theory. The adsorption energies and the changes in geometric and electronic st...

Mn-MOF-74 has great potential to catalyze selective catalytic reduction (SCR) reaction with NH3 being the reductant (NH3-SCR). However, the reaction mechanism, in particular the adsorptive properties of key reactive species in Mn-MOF-74, remains ambiguous. Besides, the effects of impurities such as H2O and SO2 on the process need further investigation. In this paper, based on density functional...

The use of zeolites for the adsorption of harmful gases has widened [1, 2]. In [2] we have studied the ionic states, motional behavior and binding degrees of SO2 and CO2 reacted with type 5A (CaA) zeolite, and we have concluded that SO2 is adsorbed on the surfaces while CO2 is absorbed in the deep pores of this zeolite. In the present work the binding states of CO2 on the same zeolite was inves...

The heterogeneous reaction SO2 + H2O2 → H2SO4 on ice at 228 K has been studied in a low temperature coated-wall flow tube. With H2O2 in excess of SO2, the loss of SO2 on an ice surface is time dependent with the reaction most efficient on a freshly exposed surface. The deactivation of the surface arises because the protons formed in the reaction inhibit the dissociation of adsorbed SO2. This lo...

An ab initio study of the adsorption processes on NOx compounds on (110) SnO2 surface is presented with the aim of providing theoretical hints for the development of improved NOx gas sensors. From first principles calculations (DFT-GGA approximation), the most relevant NO and NO2 adsorption processes are analyzed by means of the estimation of their adsorption energies. The resulting values and ...

The heterogeneous reactions of SO2 and NH3 on typical mineral oxides were investigated using in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). A new sulfate formation pathway was proposed where NH3 accelerated the formation of sulfate species. The results revealed that surface hydroxyls and oxygen played principal roles in the conversion of SO2 to sulfate. It was pro...

Graphene is an allotrope of carbon apart from graphite, diamond, fullerene and carbon nanotubes. Because graphene has unique mechanical, structural, thermal and electrochemical properties and can present the stability characteristics of these features, it becomes two-dimensional (2-d) materials which can alter three-dimensional (3-d) carbon nanotubes composite materials and has important resear...