... , add molybdenum, nickel and cobalt or other active components to prevent the catalyst from coking or poisoning.Technical Specification Type ItemHQ-MH ... every more 5% constitutes a grade, but 12 sizes by reference to the diameter, such as Φ3 ,Φ6 ,Φ8 ,Φ10 ,Φ13, Φ16 ,Φ20 ... ,Φ30 ,Φ38 ,Φ50, Φ75. The products in other grade and sizes can be designed and manufactured if to the users request. porous alumina ...