Manufacture of a silica-zirconia catalyst for conversion of hydrocarbons

Claim 1

A PROCESS FOR THE CONVERSION OF HYDROCARBONS WHICH COMPRISES CONTACTING HYDROCARBON VAPOR AT CONVERSION CONDITIONS OF TEMPERATURE AND PRESSURE WITH A CATALYST CONSISTING ESSENTIALLY OF SILLICA AND ZIORCONIA AND HAVING A ZIRCONIA CONTENT OF BETWEEN ABOUT 2 AND ABOUT 20 PERCENT BY WEIGHT, PREPARED BY A PROCESS WHICH COMPRISES REACTING A WATER-SOLUBLE ZIRCVONIUM COMPOOUND AND A SILLICATE SELECTED FROM THE GROUP CONSISTING OF AN ALKALI TION OF A GELABLE SOL CONSISTING ESSENTIALLY OF SILLICA AND ZIRCONIA CHARACTERIZED BY A PH IN EXCESS OF 6 AND A ZIRCONIA CONTENT, ON A DRY SOLIDS BASIS, OF BETWEEN ABOUT 2 AND ABOUT 20 PERCENT BY WEIGHT, PERMITTING THE SAID SOL TO SET FORMING A SILLICA-ZIRCONIA GEL, REDUCING THE PH OF SAID GEL TO BELOW 5 AND MAINTAINING THE GEL UNDER SUCH CONDITIONS OF REDUCED PH WHILE IN CONTACT WITH AN AQUEOUS ACIDIC SOLUTION AT A TEMPERATURE IN THE APPROXIMATE RANGE OF 150 TO 220* F. FOR A PERIOD OF AT LEAST ABOUT 1 HOUR UNDER CONDITIONS OF SUBSTANTIALLY ATMOSPHERIC PRESSURE, THEREAFTER WASHING THE GEL FREE OF SOLUBLE MATTER, DRYING AND CALCINING.