TECHNOLOGY FOCUS - CHEMICAL ENGINEERING - Preferred Components: The support material is contacted with the active metal component and the silica precursor and calcined to form a silicon dioxide (SiO2) layer. The support material is first impregnated/ion exchanged with the active metal component and subsequently contacted with the silica precursor to form an impregnated/ion-exchanged catalyst, and the impregnated/ion-exchanged catalyst is calcined to form a SiO2 layer. The impregnation with the active metal component, the subsequent contacting with the silica precursor and the calcination are repeated two or more times to form SiO2 layers. After contacting with the silica precursor, the BHA level decreases more than the EHA level on a percentage basis. The ratio of EHA to BHA is preferably greater than 100.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The active metal component is Group VIII metals, metal oxides, metal sulfides and/or metal carbides, especially platinum, palladium, rhodium, rhenium or iridium metal or the corresponding metal oxides, sulfides or carbides. The binder material is kieselguhr, alumina, silica or silica-alumina. When the active metal component is a noble metal,the catalyst may also include a zeolite component. EXAMPLE - 200 g of 65% ZSM-5/35% Al2O3 catalyst were impregnated via incipient wetness with tetraamine platinum chloride hexahydrate solution to produce a catalyst containing 0.1 wt.% Pt. The catalyst was dried for 4 hours at ambient conditions, dried at 250 degreesF overnight, and calcined in air at 600 degreesF for 3 hours. The catalyst had an alpha value of 620, Pt dispersion of 0.91, BHA activity of 32.6, EHA of 25400 and EHA/BHA of 779.    The catalyst was selectivated through three cycles with a silicone polymer using a standard incipient wetness process as follows. The polymer was dissolved in decane and the catalyst was impregnated with the solution. Decane was vacuum evaporated and the catalyst was left for one hour before it was dried at room temperature and then calcined at 1000 degreesF, firstly under N2 and then under N2/air. This was repeated twice. The catalyst had an alpha value of 320, Pt dispersion of 0.08, BHA activity of 0.1, EHA of 3460 and EHA/BHA of 34600, an increase in EHA/BHA of 6695%.