Kinetics and adsorption calculations: insights into the MgO-catalyzed detoxification of simulants of organophosphorus biocides,Journal of Materials Chemistry A

当前位置： X-MOL 学术 › J. Mater. Chem. A › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Kinetics and adsorption calculations: insights into the MgO-catalyzed detoxification of simulants of organophosphorus biocides
Journal of Materials Chemistry A ( IF 10.7 ) Pub Date : 2020-08-20 , DOI: 10.1039/c9ta14028j
Gizelle I. Almerindo _{1,

2,

3,

4,

5} , Suelen C. Buratto _{6,

7,

8,

9} , Eduardo H. Wanderlind _{6,

7,

8,

9,

10} , Lucas M. Nicolazi _{6,

7,

8,

9} , Patrícia Sangaletti _{6,

7,

8,

9} , Michelle Medeiros _{6,

7,

8,

9} , Felipe S. S. Schneider _{6,

7,

8,

9} , Giovanni F. Caramori _{6,

7,

8,

9} , Renato L. T. Parreira _{9,

11,

12,

13} , Gustavo A. Micke _{6,

7,

8,

9} , Haidi D. Fiedler _{6,

7,

8,

9} , Faruk Nome _{6,

7,

8,

9}

Affiliation

We report the targeted decomposition of the organophosphate methyl paraoxon by means of its transesterification with 1-propanol catalyzed by magnesium oxide. Catalyst characterization by energy dispersive X-ray fluorescence (EDXRF), nitrogen adsorption/desorption measurements (BET and BJH methods), and temperature programmed desorption of CO₂ (CO₂-TPD) showed that the employed MgO presents properties favorable for the methyl paraoxon adsorption and transesterification to occur. A thorough kinetic investigation showed that rate enhancements up to 3 × 10⁶-fold can be achieved in comparison with the spontaneous propanolysis of the substrate, and that the material can be used in additional cycles without loss of catalytic activity, with the catalyst recovery achieved through a simple washing procedure. Energies for adsorption of 1-propanol and methyl paraoxon onto a MgO model surface were obtained by density functional theory calculations, which showed that the latter displays a stronger affinity for the catalyst surface, and that the reaction should proceed with methyl paraoxon and 1-propanol molecules juxtapositioned at adjacent Mg²⁺ sites, with nucleophilic and electrophilic centers ca. 2.4 Å away from each other. Additionally, MgO also promoted rate enhancements up to 5 × 10⁴-fold in the propanolysis of a further range of representative phosphate triesters, and in most of the cases the final transesterified products are trialkyl phosphates structurally related to a family of flame-retardants. The results thus provide insights into the development of novel systems for the targeted conversion of organophosphorus compounds into value-added products by employing simple, highly efficient, and low-cost metal oxide catalysts.

中文翻译：

动力学和吸附计算：对有机磷杀生物剂的模拟物的MgO催化解毒的见解

我们报告了有机磷酸甲酯对氧磷通过与氧化镁催化的1-丙醇的酯交换反应而进行的目标分解。通过能量色散X射线荧光（EDXRF），氮吸附/脱附测量（BET和BJH方法）以及程序升温脱附的CO ₂（CO ₂ -TPD）对催化剂进行表征，表明所用的MgO具有有利于甲基对氧磷的性能发生吸附和酯交换。彻底的动力学研究表明速率提高了3×10 ⁶与底物的自然丙烷分解相比，可以实现两倍的折叠，并且该材料可以在不降低催化活性的情况下用于另外的循环中，并且通过简单的洗涤程序就可以回收催化剂。通过密度泛函理论计算获得了1-丙醇和对羟基苯甲酸在MgO模型表面上的吸附能，表明后者对催化剂表面表现出更强的亲和力，并且反应应与对羟基苯甲酸甲酯和1-丙醇一起进行分子并列在相邻的Mg ²⁺位点，具有亲核和亲电中心。彼此相距2.4Å。此外，MgO还促进了速率提高，最高可达5×10 ⁴在进一步的代表性磷酸三酯的丙烷分解中具有两倍的倍数，并且在大多数情况下，最终的酯交换产物是与阻燃剂家族在结构上相关的磷酸三烷基酯。因此，结果为采用新颖，高效和低成本的金属氧化物催化剂将有机磷化合物靶向转化为增值产品的新型系统开发提供了见识。

更新日期：2020-09-22

点击分享查看原文

点击收藏

阅读更多本刊最新论文本刊介绍/投稿指南11