Nickel sulphide, supported on SIG, exhibits a very high activity and selectivity for the direct oxidation of H2S into S at medium temperatures (100-120 degrees C) or at room temperature (20-40 degrees C). iron oxide, also supported on SIG, is highly reactive, and selective, for the same reaction at higher temperatures (210-240 degrees C). This support is very stable, insensitive to steam and to any sulphur compounds in this range of temperature.