Chemical Engineering Journal ( IF 13.3 ) Pub Date : 2023-05-15 , DOI: 10.1016/j.cej.2023.143540
Xuefan Deng , Shiying Xia , Haixu Zhao , Zhengxi Wang , Bin Qi , Xiaohai Zhou , Haibo Zhang
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Single-atom (SA) catalysts are superior in terms of catalytic activity, selectivity, and metal utilization. However, the complex preparation methods of SAs hinder their widespread application. Herein, layered double hydroxides (LDHs) with unique charge distributions were ingeniously combined with the dodecahydro-closo-dodecaborate anion [closo-B12H12]2−. We designed two different gold(Au) catalysts based on LDHs with closo-dodecaborate for the selective reduction of nitrobenzenes: composite dual-site Au SA/Au cluster catalysts (B12H12-MgAl-LDH-Au) were prepared using the anion exchangeability and spatial domain–limiting properties of LDH and the reducibility of [closo-B12H12]2−, and other Au nanoparticle catalysts (MgAl-LDH@B12H12@Au) were obtained using the reducibility of [closo-B12H12]2− immobilized on the LDH laminate. Up to 27 different nitrobenzene substrates can be selectively reduced to the corresponding azoxybenzenes (AOBs) with high efficiency at a wavelength of 450-nm radiation catalyzed by B12H12-MgAl-LDH-Au. However, large-size nanoparticles were more efficient in absorbing visible light energy. Therefore, 10 different AOB compounds were prepared using the MgAl-LDH@B12H12@Au system.
中文翻译:
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基于层状双氢氧化物和近十二硼酸盐的纳米金 (Au)、Au 团簇和 Au 单原子的形控制备及其在选择性硝基苯还原中的应用
单原子 (SA) 催化剂在催化活性、选择性和金属利用率方面具有优越性。然而,SA的复杂制备方法阻碍了其广泛应用。在此,具有独特电荷分布的层状双氢氧化物 (LDHs) 巧妙地与十二氢-环-十二硼酸阴离子 [环-B 12 H 12 ] 2−结合。我们设计了两种不同的基于 LDHs 和近十二硼酸盐的金 (Au) 催化剂用于硝基苯的选择性还原:复合双中心 Au SA/Au 簇催化剂 (B 12 H 12-MgAl-LDH-Au)是利用LDH的阴离子交换性和空间域限制特性以及[ closo -B 12 H 12 ] 2−和其他Au纳米颗粒催化剂(MgAl-LDH@B 12 H 12 @Au) 是使用固定在 LDH 层压板上的[ closo -B 12 H 12 ] 2−的还原性获得的。在 B 12 H 12催化的 450 nm 辐射波长下,最多可将 27 种不同的硝基苯底物选择性地还原为相应的氧化偶氮苯 (AOB)-MgAl-LDH-Au。然而,大尺寸纳米粒子在吸收可见光能量方面更有效。因此,使用MgAl-LDH@B 12 H 12 @Au 系统制备了10 种不同的AOB 化合物。