PREPARATION OF CARBON CATALYSTS BY HYDROTHERMAL TREATMENT OF A CARBONACEOUS HYDROGEL

The effects of hydrothermal treatment (liquid water) at 300-470-degree s-C on a carbonaceous hydrogel containing acidic functional groups wer e studied. Unlike the pyrolysis of the dried hydrogel in the absence o f water, the hydrothermal treatment converts the gel into a solid carb onaceous product characterized by a substantial pore system and residu al functional groups on the pore surface. Total pore volumes and speci fic surface areas, determined by Hg porosimetry and N2 adsorption, inc rease with the increase of the hydrothermal temperature. Surface acidi ty, however, decreases with rising hydrothermal temperature. As was sh own by the dehydration of n-butanol to form ethers and butenes, the hy drothermally prepared products are effective acidic catalysts. Their c atalytic efficiency can be raised by an increase of the area and the a cidity of the surface. Thus, the sample hydrothermally prepared at 350 -degrees-C shows the highest degree of catalytic conversion.