| 摘要 |
<p>The present invention relates to a preparation method of carbides and nitrides of transition elements in extruded shape and from their oxides, with controlled porous volume and distribution. The meso and macroporous are generated by polymeric organic molecules such as microcrystalline cellulose, which after being burned form a more opened porous structure. The molding process involves the obtention of intermediate compounds that are susceptible to peptization and later extrusion. The preparation of these compounds, with porous diameter greater than 50 angstroms, implies in a range of catalytic reactions applications since more opened porous structures allow the catalytic process of larger molecules. Besides, in this way, there are less problems related to heat and mass diffusion processes. Problems which appear when dealing with very active catalysts and/or very exothermic reactions.</p> |
