Abstract

The effect of the precipitation mode, temperature, and ZrO₂⋅nH₂O aging time on the porous texture, phase composition, and thermal transformations of ZrO₂⋅nH₂O and ZrO₂ has been studied. It has been found that varying the mode of precipitation allows changes in the specific surface area, pore volume, and average pore size of ZrO₂⋅nH₂O and ZrO₂; an increase in the contribution from mesopores to the pore space of ZrO₂⋅nH₂O; and a change the ZrO₂ particle size. It has been shown that raising the temperature of ZrO₂⋅nH₂O aging results in intense development of the mesoporous structure, an increase in the specific surface area of ZrO₂⋅nH₂O and ZrO₂, and a reduction in the size of ZrO₂ particles. At the same time, the ratio of the ZrO₂ phases undergoes a nonmonotonic change upon an increase in the period of aging. The selection of the conditions of precipitation and aging allows us to double the pore volume of ZrO₂, relative to the respective parameter of a sulfated zirconia isomerization catalyst and increase the surface area without introducing additional components. The best characteristics of the pore structure of ZrO₂ (S_sp = 140 m²/g and V_pore = 0.404 cm³/g) are achieved with precipitation at a constant pH value and subsequently aging ZrO₂⋅nH₂O for 12 h at 90°C.

中文翻译：

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通过改变ZrO 2⋅n H 2 O的析出和时效条件来控制ZrO 2的相组成和织构

摘要

研究了沉淀方式，温度和ZrO ₂ · n H ₂ O的老化时间对ZrO ₂ · n H ₂ O和ZrO ₂的多孔织构，相组成和热转变的影响。已经发现，改变沉淀方式可以改变ZrO ₂ · n H ₂ O和ZrO ₂的比表面积，孔体积和平均孔径。的增加的贡献从孔与ZrO的孔隙空间₂ ⋅ Ñ ħ ₂ O; 并更换ZrO ₂粒度。已经表明，升高ZrO ₂ · n H ₂ O的时效温度会导致介孔结构的强烈发展，ZrO ₂ · n H ₂ O和ZrO ₂的比表面积增加，并且ZrO ₂ · n H ₂ O的比表面积降低。 ZrO ₂颗粒的大小。同时，随着老化时间的增加，ZrO ₂相的比例经历非单调变化。选择沉淀和老化条件可以使ZrO ₂的孔体积增加一倍相对于硫酸化氧化锆异构化催化剂的各自参数而言，并且在不引入额外组分的情况下增加了表面积。的ZrO的孔结构的最佳特性₂（小号_SP  =140米² /克和V_孔径=0.404厘米³ /克）在恒定的pH值与沉淀得以实现，并随后老化的ZrO ₂ ⋅ Ñ ħ ₂ O代表12 h在90°C下。