| 502 / | HD | CATALYST, SOLID SORBENT, OR SUPPORT THEREFOR: PRODUCT OR PROCESS OF MAKING |
| 100 | DF | CATALYST OR PRECURSOR THEREFOR {12} |
| 232 | DF | .~ Silicon containing or process of making {2} |
| 240 | DF | .~.~ With metal, metal oxide, or metal hydroxide {8} |
| 258 | DF | .~.~.~ Of Group VIII (i.e., iron or platinum group) {3} |
| 261 | DF | .~.~.~.~ Platinum group (i.e., Ru, Rh, Pd, Os, Ir or Pt) {1} |
| 262 | | .~.~.~.~.~ Platinum or palladium |