Vogel, Roger F.; Rennard, Raymond J.; Tabacek, Joseph A.;

Process for preparing catalysts

A process for preparing novel catalysts of increased activity which comprises (1) mixing alumina with at least a Group IVB metal compound and a molybdenum compound and an aqueous solution containing at least one dissolved compound therein that imparts to said aqueous solution a pH below 6 and (2) thereafter adding to the resulting product at least one metal compound not previously added thereto.

We claim:

1. A process for preparing catalysts of increased activity which comprises (1) in a first stage mixing alumina with at least a Group IVB metal compound selected from the group consisting of TiO.sub.2, TiO.sub.2.xH.sub.2 O, TiO.sub.2, ZrO.sub.2, ZrO.sub.2.xH.sub.2 O, and HfO.sub.2 and a molybdenum compound in an aqueous solution containing at least one dissolved compound therein that imparts to said aqueous solution a pH below 6 so as to place said Group IVB metal compound and said molybdenum compound on the surface of said alumina, the resultant product containing from 20 to 50 weight percent alumina, 0.5 to 10 weight percent of said Group IVB metal compound, 0.1 to 10 weight percent of said molybdenum compound and 0.01 to 2 weight percent of said dissolved compound, drying and calcining the resultant product and (2) thereafter in a second stage adding to the resultant product a solution of at least one water soluble metal salt wherein the metal of said salt is selected from Groups IIA, IIIB and IVA of the Periodic Table, the metals V, Mn, Fe, Co, Ni, Cu, Zn, Sb, Bi, Cr and W, and the element Si drying and calcining the product of the second stage.

2. The process of claim 1 wherein the pH of said aqueous solution is in the range of about 0.1 to about 5.5.

3. The process of claim 1 wherein the pH of said aqueous solution is in the range of about 1.0 to about 5.0.

4. The process of claim 1 wherein said dissolved compound is an inorganic acid.

5. The process of claim 4 wherein said inorganic acid is nitric acid.

6. The process of claim 4 wherein said inorganic acid is hydrochloric acid.

7. The process of claim 1 wherein said Group IVB metal compound is a titanium compound.

8. The process of claim 1 wherein said Group IVB metal compound is a zirconium compound.

9. The process of claim 1 wherein said titanium compound is TiO.sub.2.

10. The process of claim 1 wherein said molybdenum compound is ammonium para molybdate.

11. The process of claim 1 wherein said molybdenum compound is MoO.sub.3.

12. The process of claim 1 wherein the components used in the first stage fall within the following ranges:

    ______________________________________
                    Weight Percent
    ______________________________________
    Alumina           25-40
    Group IVB Compound
                      1-5
    Molybdenum Compound
                      0.6-7
    Water             50-60
    Acidic Component(s)
                      0.1-0.7
    ______________________________________