State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, Liaoning, China.
State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, Liaoning, China.
J Colloid Interface Sci. 2023 Oct 15;648:169-180. doi: 10.1016/j.jcis.2023.05.144. Epub 2023 May 24.
Porous alumina has been widely used as catalytic support for industrial processes. Under carbon emission constraints, developing a low-carbon porous aluminum oxide synthesis method is a long-standing challenge for low-carbon technology. Herein, we report a method involving the only use of elements of the aluminum-containing reactants (e.g. sodium aluminate and aluminum chloride), sodium chloride was introduced as the coagulation electrolyte to adjust the precipitation process. Noticeably, the adjustment of the dosages of NaCl would allow us to tailor the textural properties and surface acidity with a volcanic-type change of the assembled alumina coiled plates. As a result, porous alumina with a specific surface area of 412 m/g, large pore volume of 1.96 cm/g, and concentrated pore size distribution at 30 nm was obtained. The function of salt on boehmite colloidal nanoparticles was proven by colloid model calculation, dynamic light scattering, and scanning/transmission electron microscopy. Afterward, the synthesized alumina was loaded with PtSn to prepare catalysts for the propane dehydrogenation reaction. The obtained catalysts were active but showed different deactivation behavior that was related to the coke resistance capability of the support. We figure out the correlation between pore structure and the activity of the PtSn catalysts associated with the maximum conversion of 53 % and minimum deactivation constant occurring at the pore diameter around 30 nm of the porous alumina. This work offers new insight into the synthesis of porous alumina.
多孔氧化铝已广泛应用于工业过程的催化载体。在碳排放量的限制下，开发一种低碳多孔氧化铝的合成方法是低碳技术的长期挑战。在此，我们报告了一种仅使用含铝反应物（如偏铝酸钠和氯化铝）的元素的方法，引入氯化钠作为凝聚电解质来调节沉淀过程。值得注意的是，通过调整 NaCl 的用量，可以改变组装氧化铝盘管的形貌，从而改变其表面的酸性和孔结构，具有火山型变化的特点。因此，得到了比表面积为 412 m/g、孔体积为 1.96 cm/g、孔径分布集中在 30nm 的多孔氧化铝。胶体模型计算、动态光散射和扫描/透射电子显微镜证明了盐对拟薄水铝石胶体纳米粒子的作用。随后，将合成的氧化铝负载 PtSn 以制备丙烷脱氢反应的催化剂。所制备的催化剂具有活性，但表现出不同的失活动力学，这与载体的抗积碳能力有关。我们发现了孔结构与 PtSn 催化剂活性之间的相关性，最大转化率为 53%，最小失活常数出现在多孔氧化铝的孔径约为 30nm 处。这项工作为多孔氧化铝的合成提供了新的思路。
