Activated carbons modified with different chemical agents such as HNO3, H2SO4, peroxyacetic acid (PAA), air, NH3 and Cl-2 have been tested as catalysts in decomposition (dehydration and dehydrogenation) of isopropanol. The majority of the samples obtained have been characterised by well-developed microporous surface with a small contribution of mesopores (8-18%). The influence of the surface area of the samples on their catalytic performance has been insignificant. The carbon oxidation with oxidants in the liquid or gas phase leads to an increased catalytic activity and the dominant process is dehydration of the alcohol studied. Carbon modification by contact with gas ammonia or chlorine results in a decrease in the catalytic activity and a significant increase in the contribution of dehydrogenation of isopropanol. It has been shown that such behaviour of the catalysts has been a consequence of changes in the acid-base character of the carbons induced by their modification.