| 502 / | HD | CATALYST, SOLID SORBENT, OR SUPPORT THEREFOR: PRODUCT OR PROCESS OF MAKING |
| 100 | DF | CATALYST OR PRECURSOR THEREFOR {12} |
| 208 | | .~ Phosphorus or compound containing same {4} |
| 209 | DF | .~.~> And vanadium containing |
| 210 | DF | .~.~> And Group VI metal (i.e., Cr, Mo, W or Po,) {1} |
| 213 | DF | .~.~> And Group VIII metal containing (i.e., iron or platinum group) |
| 214 | DF | .~.~> And silicon containing |