El Roz Ayman, Fongarland Pascal, Dumeignil Franck, Capron Mickael
CNRS, Centrale Lille, ENSCL, Université d'Artois, UMR 8181-UCCS-Unité de Catalyse et Chimie du Solide, Université de Lille, Lille, France.
Laboratoire de Génie des Procédés Catalytiques, Université Lyon 1, Villeurbanne, France.
Front Chem. 2019 Mar 27;7:156. doi: 10.3389/fchem.2019.00156. eCollection 2019.
Glycerol valorization through partial oxidation is a good way of obtaining many different molecules with high added value such as glyceric acid, tartronic acid, dihydroxyacetone, etc. Among the potential products, glyceraldehyde is an interesting chemical compound for its various applications in different domains such as organic chemistry, medical, and cosmetic industries. In the present paper, we studied the effect of different supports on the glycerol oxidation reaction in a batch reactor applying base-free conditions. The tested catalysts were Pt-based materials deposited on various supports (i.e., SiO, TiO, ZSM-5, γ-AlO), which were synthesized using a deposition method followed by a chemical reduction. The catalysts were extensively characterized (BET, ICP, XRD, TEM, XPS), highlighting differences in terms of specific surface areas, textural properties, and Pt nanoparticles sizes. We evidenced a direct relation between glycerol conversion and glyceraldehyde selectivity (i.e., an increase in glycerol conversion leads to a decrease in glyceraldehyde selectivity). The Pt/γ-AlO catalysts exhibited the highest activity, but their selectivity to glyceraldehyde significantly decreased with time on stream. Pt/SiO presented the highest selectivity to glyceraldehyde owing to a slower reaction rate, which allows envisioning technical opportunities to continuously extract the formed glyceraldehyde from the mixture.
通过部分氧化实现甘油增值是获得许多具有高附加值的不同分子的良好途径，例如甘油酸、酒石酸、二羟基丙酮等。在潜在产物中，甘油醛因其在有机化学、医学和化妆品行业等不同领域的各种应用而成为一种有趣的化合物。在本文中，我们研究了在无碱条件下的间歇式反应器中不同载体对甘油氧化反应的影响。测试的催化剂是负载在各种载体（即SiO、TiO、ZSM-5、γ-AlO）上的铂基材料，这些材料采用沉积法随后进行化学还原合成。对催化剂进行了广泛的表征（BET、ICP、XRD、TEM、XPS），突出了比表面积、织构性质和铂纳米颗粒尺寸方面的差异。我们证明了甘油转化率与甘油醛选择性之间存在直接关系（即甘油转化率的增加导致甘油醛选择性的降低）。Pt/γ-AlO催化剂表现出最高的活性，但其对甘油醛的选择性随反应时间显著降低。Pt/SiO对甘油醛具有最高的选择性，这是由于反应速率较慢，这使得我们能够设想从混合物中连续提取生成的甘油醛的技术机会。
