Preparation, Characteristic Description And Applied Study Of The [NZP] Family Supporters Of Catalyst

The matrix of [NZP] family phosphate materials is natrium phosphate zirconium, its molecular formula is NaZr₂ (PO₄)₃.If other metal ions take place of the natrium ion;there are a series of same structural ramification. They are called the [NZP] Family Compound. Materials from the kind of Compound take on steady framework, favorable thermal-stability, low-thermal distensibility.Because of these traits, the [NZP] family phosphate materials have been used as a potential new material in many areas, including catalyst supporter, automobile engine components, heat exchangers and coating materials for space technology.Five different compositions belonging to [NZP] family supporters were synthesized by the coprecipitation method. Respectively, they are KZr₂(PO₄)₃(coded by KZP),CaZr₄(PO₄)₆(coded by CZP),SrZr₄(PO₄)₆(coded by SZP),Sr_0.5KZr₂(PO₄)₃(coded by SKZP),Ca_0.5Ba_0.5Zr₄(PO₄)₆(coded by CBZP). These carriers were characterized by X-ray diffraction (XRD) and BET method. Base on them, choosing the active prescription of S101 vanadium catalyst which was used widely in production of the sulfuric acid, The [NZP] family supporters have been used to apply to be the carrier of vanadium catalyst. The oxygenation reaction of sulfur dioxide was applied to probe test, the activities of above new vanadium catalysts were tested in small type of fixed-bed reactor according to these standards of chemical industry. It is searched after simply on the influence of specific surface areas, average diameter of pours and chemical composing of these carriers as well as the influence of different preparation methods of catalyst on catalyst performance. The experimental results indicate:1. The specific surface areas of [NZP] family supporters synthesized by the coprecipitation method are between 15 to 30m2 · g^-1. The average diameter of pours of above supporters is between 15 to 25nm. The [NZP] family supporters belong to the supporter materials of middle specific areas and small average diameter of pours.2. Contrasting the vanadium catalysts prepared by wet-blend method and steep method, the outcome is that active component of catalysts prepared by wet-blend is dispersed better.3. The content of vanadium pentoxide with the [NZP] family material as supporter of vanadium catalysts can keep at about 8 percent, and the heap-density of above catalysts can be close to 0.6 g ? mL'1. Contrasting with that of industrial finished vanadium catalyst with diatomite as the carrier, both of them meet the request of SI 01 industrial, vanadium catalyst.4. The activities of vanadium catalysts debase in turn from V2O5/KZP, V2O5/CZP, V2O5/SZP, V2O5/CBZP to V2O5/SKZP. Experimental results prove that the activities of three catalysts (V2O5/KZP, V2O5/CZP, and V2O5/diatomite) are similar, but their activities are lower than that of industrial finished vanadium catalyst.5. In these different Supporters of the [NZP] Family, KZP supporter doesn't react with the other components of SI01 vanadium catalyst. It is suitable to be a new candidate supporter of S101 vanadium catalyst because of its stable chemical property.Except KZP, ion substitution can take place in other supporters coded by CZP, SZP, SKZP and CBZP during the preparing process. Ca2+,Ba2+ or Sr2+ in the other supporters may react with SO42" to become CaSO4,BaSO4 or SrSC^. Therefore, those primary supporters such as CZP, SZP, SKZP and CBZP have converted into KZP. As a result, they are not suitable to be the candidate supporter of SI 01 vanadium catalyst.