Catalysts having structures containing the Mo6S8 cluster (crystalline Chevrel phases, amorphous ternary molybdenum sulfides, and ligated molecular clusters) have been discovered to be active for thiol synthesis from methanol and hydrogen sulfide at 250 degreesC and 1 atm. An amorphous lanthanum molybdenum sulfide material was found to be the most selective catalyst (>80% methanethiol) at low conversions. CO2, CO, CS2, and CH4 were the major by-products in these studies.