Gas Phase Glycerol Valorization over Ceria Nanostructures with Well-Defined Morphologies.
Gas Phase Glycerol Valorization over Ceria Nanostructures with Well-Defined Morphologies.
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气相甘油在具有明确形态的陶瓷纳米结构上价值。
DOI：
10.1021/acscatal.0c05606
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发表时间：
2021-04-16
期刊：
影响因子：
12.9
通讯作者：
Hutchings GJ
中科院分区：
文献类型：
--
作者：
Smith LR;Sainna MA;Douthwaite M;Davies TE;Dummer NF;Willock DJ;Knight DW;Catlow CRA;Taylor SH;Hutchings GJ
甘油溶液被蒸发并在不同形貌的二氧化铈催化剂上反应，以研究产物分布与暴露表面的关系，特别是生物可再生甲醇的产率。通过改变沉淀剂浓度或合成温度，通过水热合成制备具有立方体、棒状和多面体形态的二氧化铈。发现具有立方形态的二氧化铈的甘油转化率较低，这归因于较低的表面积和相对较高的酸度。密度泛函理论计算还表明，（100）表面可能在反应条件下被羟基化，这可能限制碱性位点的可用性。在 400 °C 下，多面体二氧化铈样品的甲醇时空产率是立方材料的四倍多，其中每千克催化剂每小时产生 201 克甲醇。在可比的甘油转化率下，我们表明棒状和多面体催化剂产生甲醇的主要中间体羟基丙酮（HA），选择性约为。 45%，但对于立方体样品，发现该值为 15%。这相当于 320 °C 下多面体样品的 HA 时空产率比立方体样品增加了 13 倍。就反应机理讨论了这种差异的含义，表明立方催化剂与棒状和多面体催化剂的机理不同。二氧化铈的暴露表面与高甲醇产率之间的密切关联是该领域未来催化剂设计的重要考虑因素。
Glycerol solutions were vaporized and reacted over ceria catalysts with different morphologies to investigate the relationship of product distribution to the surface facets exposed, particularly, the yield of bio-renewable methanol. Ceria was prepared with cubic, rodlike, and polyhedral morphologies via hydrothermal synthesis by altering the concentration of the precipitating agent or synthesis temperature. Glycerol conversion was found to be low over the ceria with a cubic morphology, and this was ascribed to both a low surface area and relatively high acidity. Density functional theory calculations also showed that the (100) surface is likely to be hydroxylated under reaction conditions which could limit the availability of basic sites. Methanol space-time-yields over the polyhedral ceria samples were more than four times that for the cubic material at 400 °C, where 201 g of methanol was produced per hour per kilogram of the catalyst. Under comparable glycerol conversions, we show that the rodlike and polyhedral catalysts produce a major intermediate to methanol, hydroxyacetone (HA), with a selectivity of ca. 45%, but that over the cubic sample, this was found to be 15%. This equates to a 13-fold increase in the space-time-yield of HA over the polyhedral samples compared to the cubes at 320 °C. The implications of this difference are discussed with respect to the reaction mechanism, suggesting that a different mechanism dominates over the cubic catalysts to that for rodlike and polyhedral catalysts. The strong association between exposed surface facets of ceria to high methanol yields is an important consideration for future catalyst design in this area.
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DOI：
10.1002/ep.10225
发表时间：
2007-12-01
期刊：
ENVIRONMENTAL PROGRESS
影响因子：
--
作者：
Johnson, Duane T.;Taconi, Katherine A.
通讯作者：
Taconi, Katherine A.
影响因子：
7.3
作者：
Corma, Avelino;Huber, George W.;O'Connor, Paul
通讯作者：
O'Connor, Paul
影响因子：
5.5
作者：
Hernandez, Diana;Velasquez, Mauricio;Batiot-Dupeyrat, Catherine
通讯作者：
Batiot-Dupeyrat, Catherine
影响因子：
2.5
作者：
Askrabic, S.;Dohcevic-Mitrovic, Z. D.;Popovic, Z. V.
通讯作者：
Popovic, Z. V.
影响因子：
12.9
作者：
Aneggi, Eleonora;Wiater, Dawid;Trovarelli, Alessandro
通讯作者：
Trovarelli, Alessandro