| 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} |
| 243 | DF | .~.~.~ Of Group I (i.e., Alkali, Ag, Au or Cu) {1} |
| 244 | | .~.~.~.~ Of copper {1} |
| 245 | DF | .~.~.~.~.~> And group VIII metal containing (i.e., iron or platinum group) |