The invention, belonging to the technical field of catalyst and its application, particularly relates to an ultrafine
molecular sieve structured catalytic material based on a
porous silicon carbide carrier and a preparation method thereof. The material comprises ultrafine
molecular sieve crystals as active elements and has a hierarchically porous structure, and the whole ultrafine
molecular sieve coating has catalytic activity. The method is characterized by
coating a colloidal molecular
sieve precursor on the surface of a modified foam
silicon carbide carrier, converting the molecular
sieve precursor into ultrafine molecular
sieve crystals by
vapor phase treatment to realize the firm combination between the
coating and the carrier. According to the invention, by controlling the synthesis conditions of the colloidal molecular sieve precursor and the method of adding a pore forming agent, the size of the molecular sieve crystals, silica-
alumina ratio and intercrystalline
porosity can be controlled; a pore structure and the type of the molecular sieve can be designed according to the geometrical structure of a target product; and the capacity of accommodating carbon is raised, the
mass transfer capability of the catalyst is reinforced, and the life of catalyst is prolonged while keeping the
high activity of the ultrafine molecular sieve and high target product selectivity.