A method for the preparation of microporous materials, which is coated with oxides of the rare earth metals are

摘要

A process that provides a catalytic rare earth oxide-coated microporous free-flowing bulk particulate wherein the amount of metal oxide coated thereon is high, without jeopardizing the effectiveness of the material. The rare earth metal oxide coated on the outer surface may be in the range of 20 to 70% by weight based on the total equivalent rare earth metal oxide and microporous particulate material content. In particular, a zeolite free-flowing bulk particulate having high loadings of rare earth metal oxide tends to be quite stable. For instance, when the rare earth metal oxide-coated zeolite free-flowing bulk particulate has been heat treated at tempertures less than about 200°C and then slurried in water, typically, less than 30% by weight of the rare earth metal oxide (based of the total equivalent rare earth metal oxide content) is found to leach into water. This material has been found to have minimal leachability when heat treated above 400°C.