Temperature influence on ozone generation and decomposition on solid surfaces

This master’s thesis is focused on a study of temperature influence on ozone generation and decomposition by chosen solid surfaces. Ozone is unstable gas that is decomposed spontaneously. This decomposition can be accelerated by various factors such as increase in temperature or reaction with other substances. The aim of this study is to determinate how fast the ozone decomposition proceeds at different temperatures and how the homogenous decomposition of ozone is accelerated by heterogeneous processes on the walls of solid materials. Currently in practise ozone is used in many areas and the finding of the rate of its decomposition can help to increase efficiency of its production and subsequent specific applications. In the theoretical part of the thesis, these points are described: important properties of ozone, possibilities of its utilization, the ozone generation, some methods of determination of the ozone concentration, ozone relationship to various solid surfaces and present theoretical knowledge about the effect of temperature on the ozone generation and decomposition. In the experimental part, the rate of the ozone decomposition in reaction tubes made of copper and iron of two different surface to volume ratios was investigated at temperatures of 10, 25, 40, 55, 70 and 85 °C. Ozone generated from oxygen was closed in the reaction tube and the decrease of its concentration during the time was observed by absorption spectroscopy. From obtained exponential dependencies, the rate constants at different conditions of this experiment were evaluated. The rate of ozone decomposition significantly increased with higher temperature. The fastest ozone decomposition took place in the iron tube of larger inner diameter (8 mm)