Cobalt-based single-atom dehydrogenation catalysts having improved thermal stability and method for producing olefins from corresponding paraffins by using the same

A method for preparation of a single-atom cobalt-based catalyst, which comprises the steps of:

• a) thermally treating silica as a support at a temperature ranging from 600 to 870° C. to induce shrinkage of the support, and simultaneously to remove its surface hydroxyl groups, followed by subjecting the shrunken support to a high-temperature aqueous treatment in a temperature range of 70 to 150° C. to afford a pretreated silica having hydroxyl groups selectively activated thereon;
• b) preparing an aqueous dispersion of the pretreated silica;
• c) preparing a pH-adjusted aqueous dispersion of the pretreated silica by adding a base to the aqueous dispersion of the pretreated silica to adjust the pH of the dispersion to at least 10;
• d) separately preparing a pH-adjusted cobalt precursor aqueous solution by preparing an aqueous solution of a cobalt precursor having an oxidation number of 3+ and adding a base to the aqueous solution;
• e) combining the pH-adjusted aqueous dispersion of the pretreated silica with the pH-adjusted aqueous solution of the cobalt precursor to afford an aqueous dispersion in which at least a part of the cobalt ions having an oxidation number of 3+ is adsorbed onto the surface of the pretreated silica;
• f) removing cobalt ions which remain not adsorbed onto the pretreated silica;
• and
• g) thermally treating the cobalt ion-adsorbed silica obtained in step f);
• wherein cobalt having an oxidation number of 2+ exists in an isolated form of single-atom on the pretreated silica while being tetrahedrally coordinated at trihydroxyl groups present on the surface of the pretreated silica.