What other substances can be used for sulfiding pre-hydrogenated iron-molybdenum catalysts besides CS2?

Dimethyldisulfide can be used for vulcanization.

The presulfiding catalyst Techwell 321C (T321C) is a sulfur-rich isobutylene sulfide produced using a new chlorine-free process. As a commonly used sulfurizing agent in the catalyst presulfiding process, it features high activity, a wide decomposition temperature range, as well as a light color, low toxicity, and no irritating odor. The pre-vulcanization process outside the reactor can reduce the vulcanization time, ensure uniform catalyst vulcanization, and improve the hydrogenation activity, stability, and selectivity of the catalyst, thereby enabling maximum effective utilization of the catalyst. Technical Specifications Item Test Method Appearance Pale yellow liquid Visual inspection Kinematic viscosity, 100°C, mm2/s 1.0–2.0 ASTM D445 Flash point (open cup), °C 95 min ASTM D92 Density, 20°C, kg/m3 950–1150 ASTM D1298 Mechanical impurities, % (m/m) 0.05 max ASTM D4951 Moisture, % (m/m) Trace amounts ASTM D95 Sulfur, % (m/m) 50–60 ASTM D129 Chlorine, % (m/m) None ASTM D4951 Precautions: When storing, handling, or mixing this product, the maximum temperature should not exceed 85°C℃ ； For long-term storage, the maximum temperature should not exceed 45°C. This product is not flammable, explosive, or corrosive, and no special precautions are necessary during use; however, general precautions for handling concentrated chemicals and adding additives to base oils should be followed. If swallowed accidentally, it can be toxic, but not more so than ordinary petroleum products ； If it comes into contact with the skin, it can be thoroughly washed clean using detergent, soap, and water. Comparison of Isobutylene Sulfide (T321C) (U.S. SZ-54 and T321C)
I. Appearance comparison: (SZ-54 on the left, T321C on the right)
Flavor: SZ-54: Strong flavor; T321C: Relatively mild flavor.
II. Infrared comparison: Both do not contain chlorine.
Note: Red represents the SZ-54 sample, blue represents T321C.
III. Comparison of main components: (Chromatographic analysis)
Note: Red represents the SZ-54 sample, blue represents T321C.
IV. Comparison of key test parameters

| Parameter | T321C | SZ-54 sample | Test standard |
|-----------|-------|--------------|----------------|
| Moisture, % (V/V) | Trace | Trace | **Standard test method** |
| Mechanical impurities, % (m/m) | Not more than 0.05 | 0.05 | |
| Flash point (open cup), °C | 107 | 108 | |
| Kinematic viscosity (100°C), mm²/s | 4.35 | 4.85 | |
| Density (20°C), kg/m³ | 1.16 | 1.17 | |
| Oil solubility | Transparent, no precipitate | Transparent, no precipitate | |
| Sulfur content | 56 | 53 | |
| Chlorine content, % (m/m) | None | None | |
| Copper corrosion (121°C, 3h), grade | Greater than 3c | Greater than 3c | |
| Freezing test (-25°C) | No precipitation | No precipitation | |