| 502 / | HD | CATALYST, SOLID SORBENT, OR SUPPORT THEREFOR: PRODUCT OR PROCESS OF MAKING |
| 100 | DF | CATALYST OR PRECURSOR THEREFOR {12} |
| 208 | DF | .~ Phosphorus or compound containing same {4} |
| 210 | DF | .~.~ And Group VI metal (i.e., Cr, Mo, W or Po,) {1} |
| 211 | | .~.~.~ Molybdenum {1} |
| 212 | DF | .~.~.~.~> And bismuth containing |