Hydrotheral Synthesis And Characterization Of Open Framework Vanadium, Iron-phosphates Doping With Al

Extensive studies have been devoted to the syntheses and characterization ofvanadium and iron phospates with open framework structures because of theirpotential usage in the field of catalysis, molecular sieves, ionic exchange and gasseparation. However to make the microporosity of these compounds actual applicable,the templates have to be removed from the tunnels or pores of the structure, usuallyby calcination which inevitably leads to the collapse of the framework of thesephosphates. So the thermal stability is crucial to these group of compounds.This thesis aims to the improvement of the thermal stability of[H3N(CH2)2NH3]2[H3N(CH2)2NH3][VIII(H2O)2(VIVO)8(OH)4(PO)4(HPO4)4(H2O)2]·2H2O(the following textshortened form V9P8-en ),[H3NCH2CH2NH3]0.5 [Fe(OH)(PO4)]and [Fe2NH4(OH)(PO4)2]·2H2O by doping with Al.Experiments been conducted andresults obtained are as follows:1. By adding Al into V9P8-en, researching the order of doping the reactants, thepH of originative gel, the reactants' filling volume, the form of Al source and V source,the effect that the additive rate of V : P : Al have on the productions and so on, getsome data. The result shows that these factors have different influences on thegranularity and products yield of blue block crystal, the main production;however,the pH and filling volume have the most obvious effect. We find out that besides themain phase blue flaky crystals, there are also some aqua needle-shaped crystals andblack phases. When the number of the granularity and products yield reach the top,the formulation is V:V2O5:AlCl3:H2O:H3PO4(85%):en:HAc =0.0254g:0.1821g:0.0408g:19.40ml:0.23ml:0.26ml:0.16ml,pH=4.7 and the filling volume is 50%.After we analyzed the production, we discovered that the phase of blue flaky isV9P8-en and the aqua needle-shaped is V2P3-en. The result of the analysis on both ofthe two elements by EMPA tells us that there is no Al get into the framework.2. The experiment of [Fe2NH4(OH)(PO4)2]·2H2O with doping the elementary Alhas been carried out as well as the experiment of [H3NCH2CH2NH3]0.5[Fe(OH)(PO4)]with the elementary Al doped, and we get the parallel results. The experimentalproducts with different quantity of Al have been analyzed separately through XRDand it has been revealed that the production phase, doped in the elementary Al, remainunchanged;separate analysis of the experimental products with different quantity ofthe elementary Al through EMPA and chemical component analysis and the resultturns out that comprehensive products contain Al and in addition ratio of the contentAl to Al doping is direct, which is the demonstration of the component analysis;thecalculation of the crystal parameter comes to a slight variety of the crystal parameteras the join of Al. The analysis of the TGA-DTA of the comprehensive products provesthat the variety of the thermal stability is not that apparent, with its specific causeswaiting for further exploration.