Necessity of calcination in the preparation of phosphotungstic acid@TiO2 composites. A case study on the facile sol-gel synthesis of nanospheres and their superior performance in catalytic oxi-desulfurization
Necessity of calcination in the preparation of phosphotungstic acid@TiO2 composites. A case study on the facile sol-gel synthesis of nanospheres and their superior performance in catalytic oxi-desulfurization
复制标题
磷钨酸@TiO2复合材料制备过程中煅烧的必要性
DOI：
10.1039/c7nj01234a
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发表时间：
2017
影响因子：
3.3
通讯作者：
Qin Libo
中科院分区：
文献类型：
--
作者：
Zuhra Zareen;Lei Huan;Zhao Zipeng;Zhou Yunshan;Zhang Lijuan;Qin Libo
煅烧被认为是制备二氧化钛基催化剂过程中的关键步骤;然而，它消耗大量的能量。本文首次明确指出，在制备磷钨酸负载量为10- 40wt%的磷钨酸@二氧化钛（PW 12@TiO 2）催化剂时，高能耗的煅烧是一个多余的过程。为了证明这一点，PW12@TiO 2纳米球通过溶胶-凝胶过程的制备的案例研究进行了讨论。采用FT-IR、FT-Raman、BET、XRD、ICP和SEM等分析手段对纳米球的结构和形貌进行了表征。使用这些纳米球研究了由350 ppmwS二苯并噻吩（DBT）在正辛烷中组成的模型油的氧化脱硫。结果表明，煅烧前后的PW12@TiO2纳米球在模拟油中均表现出了几乎平行但优异的氧化脱硫性能。在60 °C下，使用70 mg具有30重量%PW 12负载的煅烧和未煅烧的PW12@TiO 2纳米球，在2小时内将20 mL正辛烷中350 ppmwS的硫含量分别降至2.4和2.6ppmwS。催化剂经10次再生后仍保持较高的脱硫效率。这种优异的脱硫性能使得不经焙烧处理的复合催化剂在实际氧化脱硫过程中具有很好的应用前景。
Calcination is considered to be a key step in the process of preparation of titanium dioxide based catalysts; however, it consumes a lot of energy. We describe unequivocally here for the first time that high-energy consuming calcination is a surplus process in the preparation of phosphotungstic acid@titanium dioxide (PW12@TiO2) catalysts with various loadings of phosphotungstic acid (10–40 wt%) for oxidative catalytic reactions. To prove this, a case study on the preparation of PW12@TiO2 nanospheres via the sol–gel procedure is discussed here. The structure and morphology of the nanospheres were characterized by FT-IR, FT-Raman, BET XRD, ICP and SEM analyses. Oxidative desulfurization of a model oil composed of 350 ppmwS dibenzothiophene (DBT) in n-octane was investigated using these nanospheres. The results showed that both calcinated and un-calcinated-PW12@TiO2 nanospheres exhibited almost parallel yet excellent oxidative desulfurization performances in the model oil. The 350 ppmwS of sulfur content in 20 mL of n-octane was dropped down to 2.4 and 2.6 ppmwS within 2 hours at 60 °C using 70 mg of calcinated and un-calcinated-PW12@TiO2 nanospheres with 30 wt% PW12 loading, respectively. The high desulfurization efficiency of the catalyst remained unchanged even after the regeneration of the catalyst ten times. This excellent desulfurization performance makes the as-prepared composite without calcination treatment a promising catalyst in practical oxidative desulfurization processes.