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首页> 外文期刊>Thermochimica Acta: An International Journal Concerned with the Broader Aspects of Thermochemistry and Its Applications to Chemical Problems >THERMOCHEMICAL EFFECTS IN THE DEVELOPMENT OF MESOPOROUS ALUMINO-PHOSPHORO-VANADATES FROM AMMONIUM NITRATE PRECURSORS
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THERMOCHEMICAL EFFECTS IN THE DEVELOPMENT OF MESOPOROUS ALUMINO-PHOSPHORO-VANADATES FROM AMMONIUM NITRATE PRECURSORS

机译：硝酸铵前体对亚铝磷酸盐-钒衍生物的热化学作用

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Mesoporous alumino-phosphoro-vanadate solids were prepared by heating precipitates of the corresponding metals containing ammonium nitrate salts. The materials obtained contained the elements Al:P:V=100:X:Y, where X, Y=O, 5, 10, 20 (16 samples overall). Thermogravimetric analysis showed that the addition of P or V in the solids influences the endo- and exothermicity of the NH4NO3 decomposition, driving the net result from highly endothermal at no addition of P and/or V to almost neutral at high addition (20%) of those heteroatoms. The activation energies, calculated according to the Coats-Redfern procedure, were found to increase on adding 5% of P or V and then to drop at higher addition. The order of the decomposition reaction drops from approximate to 0.5 to 0 at 20% of P and/or V heteroatoms. The materials obtained had a high surface area (BET) which increases from 200 m(2) g(-1) for pure alumina to almost 400 m(2) g(-1) on addition of 5-10% of P and/or V, while further addition of those heteroatoms decreases the surface area to its original values. The maximum of the surface area appears in samples where the NH4NO3 decomposition follows almost equal endothermic and exothermic routes. (C) 1997 Elsevier Science B.V. [References: 12]
机译：通过加热相应的含有硝酸铵盐的金属的沉淀物来制备介孔的铝-磷-钒酸盐固体。获得的材料包含元素Al：P：V = 100：X：Y，其中X，Y = O，5、10、20（总共16个样品）。热重分析表明，固体中添加P或V会影响NH4NO3分解的吸热和放热，从而将不添加P和/或V的高吸热性转变为高添加（20％）时几乎为中性的最终结果那些杂原子。发现根据Coats-Redfern程序计算的活化能在添加5％的P或V时增加，然后在增加时降低。在20％的P和/或V杂原子下，分解反应的顺序从大约0.5下降到0。获得的材料具有较高的表面积（BET），在添加5-10％的P和/时，其表面积从纯氧化铝的200 m（2）g（-1）增加到几乎400 m（2）g（-1）。或V，同时进一步添加那些杂原子将表面积减小至其原始值。表面积的最大值出现在样品中，NH4NO3分解遵循几乎相等的吸热和放热途径。 （C）1997 Elsevier Science B.V. [参考：12]

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