Surfactant effects on the synthesis of porous cerium oxide from a type IV deep eutectic solvent
Surfactant effects on the synthesis of porous cerium oxide from a type IV deep eutectic solvent
复制标题
DOI：
10.1039/d2ta05693c
复制
发表时间：
2022-08-08
影响因子：
11.9
通讯作者：
Edler, Karen J.
中科院分区：
文献类型：
--
作者：
Manasi, Iva;Andalibi, Mohammad R.;Edler, Karen J.
在这项工作中，我们提出了一种新的，低温和绿色的原子效率溶剂热合成的结晶，胶束模板铈IV氧化物（二氧化铈）从IV型低共熔溶剂（DES）包括水合铈含金属盐，硝酸铈（iii）六水合物（Ce（NO3）（3）中心点6 H（2）O），和氢键供体，尿素，摩尔比为1：3.5。最近在六水合硝酸铈：尿素DES中报道了离子和非离子表面活性剂的自组装纳米结构[Manasi等人，J. Chem. Phys.，2021，155，084902]，其可用于从这些溶液生产纳米模板化的二氧化铈。在这项工作中，我们在DES中使用了C-12和C-16烷基链长的阳离子表面活性剂（C（n）TAB和C（n）TANO（3））和C-16烷基链长的非离子表面活性剂BrijC（10）的高浓度（20%w/w）溶液，以改变所产生的氧化铈的孔隙率。氧化铈的表征已经使用SEM/TEM、N-2吸附、SAXS和TPR进行，以理解和量化结晶度、形态和孔隙率的性质，沿着CO氧化以用于材料的催化活性。通过该方法生产的氧化铈具有2-5 nm尺度的孔隙率和取决于表面活性剂的量和类型在40和150 m2/g之间的BET表面积。使用无卤化物的阳离子表面活性剂制备的材料显示出上级催化活性和低活化能沿着高孔隙率，并且在许多工业应用中呈现出改善二氧化铈性能的潜力。
In this work we present a novel, low temperature and green method for atom-efficient solvothermal synthesis of crystalline, micelle templated cerium IV oxide (ceria) from a type IV deep eutectic solvent (DES) comprising a hydrated cerium containing metal salt, cerium(iii) nitrate hexahydrate (Ce(NO3)(3)center dot 6H(2)O), and a hydrogen bond donor, urea, in a molar ratio of 1 : 3.5. Self-assembled nanostructures of ionic and non-ionic surfactants have been recently reported in a cerium nitrate hexahydrate : urea DES [Manasi et al., J. Chem. Phys., 2021, 155, 084902], which can be exploited to produce nano-templated ceria from these solution. In this work, we have used high concentration (20% w/w) solutions of C-12 and C-16 alkyl chain length cationic surfactants (C(n)TAB and C(n)TANO(3)) and C-16 alkyl chain length non-ionic surfactant BrijC(10) in the DES to alter the porosity of the cerium oxide produced. The characterisation of the cerium oxide has been carried out using SEM/TEM, N-2 sorption, SAXS and TPR to understand and quantify the nature of the crystallinity, morphology and porosity along with CO oxidation for the catalytic activity of the material. The cerium oxide produced by this method has porosity on the 2-5 nm scale and a BET surface area between 40 and 150 m(2) g(-1) depending on the amount and type of surfactant. Materials prepared using halide-free cationic surfactants show superior catalytic activity and low activation energies along with high porosity and present potential for improved ceria performance in many industrial applications.