PURPOSE: To obtain a catalyst for selective synthesis of mercaptans by converting a surface of a natural Al oxide-contg. material, a synthetic Al oxide or an Al hydroxide, an Al salt or an Al alcoholate into an alumina gel, converting the gel into alumina trihydrate, and then treating it with a sulfiding agent.

CONSTITUTION: At least, a surface of a natural Al oxide-contg. material, a synthetic Al oxide or an Al hydroxide (such as boemite), an Al salt or an Al alcoholate is treated with an aq. soln. of an alkali metal or alkali earth metal oxide, by which it is converted into an amorphous alumina gel. The gel is heated and maintained at a temp. sufficient to convert the gel into crystalline α- and/or β-alumina trihydrate, and then treated with a sulfiding agent (such as hydrogen sulfide) at a temp. and a pressure for a time sufficient to form the sulfided product.