<p>An <i>operando</i> Fourier transform infrared (FTIR) spectroscopy study of the catalytic conversion of isopropanol over a monolayer V₂O₅/TiO₂ catalyst was carried out at atmospheric pressure in a temperature range of 50–300&#xa0;°C. The experiments were carried out using two FTIR spectrometers, which allowed us simultaneously to study the catalyst under reaction conditions, to analyze reaction products in the gas-phase, and to determine the isopropanol conversion. In addition, the catalyst state was analyzed by X-ray photoelectron spectroscopy (XPS) after treatments under reaction conditions. It was found that the reaction starts above 100&#xa0;°C, the conversion of isopropanol increases with temperature, achieving 60% at 300&#xa0;°C. The gaseous products include propylene, acetone, CO, and CO₂, with propylene being the main reaction product above 200&#xa0;°C. It was also found that at low temperatures (between 50 and 150&#xa0;°C), the main reaction intermediate adsorbed on the catalyst surface is molecular isopropanol, which is typical of the concerted elimination mechanism for the dehydration of isopropanol. At higher temperatures, there appear adsorbed acetone and carboxylate species on the catalyst surface. The overall mechanism for the catalytic conversion of isopropanol on supported vanadium oxide catalysts is discussed.</p> Graphical abstract <p></p>