Kinetics of ozone decomposition in porous In₂O₃ monoliths

Abstract

The performance of many chemical gas-phase reactions is strongly influenced by the interaction of reactants with interfaces. Nanoporous materials, which exhibit pore diameters up to 100 nm and high specific surface areas, can be utilized to reduce the amount of cost-intensive materials (e.g. noble metals). However, due to limitations in material transport and reaction kinetics detailed knowledge of the diffusion and the kinetics of a chemical reaction is necessary to improve the performance of chemical processes in industry and research. To experimentally study the diffusion and reaction kinetics of gaseous species inside such pores, the chemoresistive behavior of certain metal oxides such as InO can be utilized. In this work, we present a model system based on hierarchically porous monolithic indium oxide (InO) which allows the determination of kinetic effects by utilizing its gas transducing properties. The experimental data obtained by electrical measurements are compared to two diffusion and diffusion-reaction models. Using these methods, the rate constant of ozone decomposition in porous InO is estimated. The results are the basis for a suitable material design for semiconducting gas sensors, on the nano-, meso- and macroscale, which helps in understanding the underlying mechanisms of diffusion and reaction.

Direct 3D Printing of Reactive Agitating Impellers for the Convenient Treatment of Various Pollutants in Water

“…However, the diffusion was determined by both flow velocity of liquid phase and micro/nanostructure of materials. Therefore, researchers optimize the diffusion process through reasonable physical and chemical method to enhance mass transfer even at molecular level . Stirring is probably the most commonly used method to promote the mixture and diffusion of reactants .…”

Modeling of a Hybrid Langmuir Adsorption Isotherm for Describing Interactions Between Drug Molecules and Silica Surfaces

“…Ordered mesoporous materials have raised great attention in different fields of application such as sorption 1,2 , heterogeneous catalysis 1,3,4 , energy storage/conversion [5][6][7] , (gas)sensing [8][9][10] , and drug delivery. 11,12 Especially in the area of drug delivery, these materials bear big potential due to their large surface area and narrow pore size distribution, which enables individual design of the nanocarriers depending on the drug and the area of application.…”

“…surface inhomogeneity, (various) reactive sites, pore diffusion, and reactivity. 2,10,[13][14][15][16][17] Thus, deep insights into the interactions between drug molecules and the adsorbent are required to understand and optimize the drug delivery process. Tang et.…”