Yuan-Yuan Jiang,Hong-Bin Dai,Yu-Jie Zhong,De-Min Chen,Ping Wang
Graphical Highly active and robust : Ni–Pt alloy nanocatalysts supported on mesoporous ceria, prepared by a one-pot evaporation-induced self-assembly method, selectively promote decomposition of hydrazine monohydrate at a high rate to generate hydrogen with high selectivity (see figure). Moreover, the catalysts exhibit high cycle stability. The development of active, selective, and robust catalysts is a key issue in promoting the practical application of hydrazine monohydrate (N 2 H 4 ⋅ H 2 O) as a viable hydrogen carrier. Herein, the synthesis of a supported Ni–Pt bimetallic nanocatalyst on mesoporous ceria by a one-pot evaporation-induced self-assembly method is reported. The catalyst exhibits exceptionally high catalytic activity, 100 % selectivity, and satisfactory stability in promoting H 2 generation from an alkaline solution of N 2 H 4 ⋅ H 2 O at moderate temperatures. For example, the Ni 60 Pt 40 /CeO 2 catalyst enabled complete decomposition of N 2 H 4 ⋅ H 2 O to generate H 2 at a rate of 293 h −1 at 30 °C in the presence of 2 M NaOH, which compares favorably with the reported N 2 H 4 ⋅ H 2 O decomposition catalysts. Phase/structural analysis by XRD, TEM, and Auger electron spectroscopy was conducted to gain insight into the excellent catalytic performance of the Ni–Pt/CeO 2 catalyst.
A clean and highly efficient synthesis of 1-amino-2-acetylanthraquinone via reductive isoxazole ring cleavage of 3-methylanthra[1,2- c ]isoxazole-6,11-dione catalyzed by trace copper using hydrazine hydrate as a clean reducing agent and water as a green reaction medium under mild reaction conditions was investigated. Various transition-metal catalysts were screened for the reductive ring-opening reaction, and Cu(NO 3 ) 2 was shown to be an excellent catalyst. A conversion of 97.2% and 1-amino-2-acetylanthraquinone selectivity greater than 95% were obtained in the presence of 2.6 mol% Cu(NO 3 ) 2 (turnover number 38) with 1.3 equiv. of hydrazine hydrate for 2 h in water. The structure of the product was confirmed by 1 H nuclear magnetic resonance spectroscopy and mass spectrometry ; the main byproduct was hydroxyl-substituted 1-amino-2-acetylanthraquinone. A possible reaction mechanism for the copper-catalyzed ring cleavage of 3-methylanthra[1,2- c ]isoxazole-6,11-dione with hydrazine hydrate was proposed.
Jia Wang,Yajie Zhang,Jiangyong Diao,Jiayun Zhang,Hongyang Liu,Dangsheng Su
A highly efficient and reusable plane-curved and interlayer-expanded MoS 2 nanocatalyst with increased exposure of active sites was prepared. The catalyst was used for the heterogeneous hydrogen transfer reaction of nitroarenes with hydrazine monohydrate as a reductant under mild reaction conditions without pressure and base, which was different from other hydrogen transfer systems that require the presence of a base (e.g., propan-2-ol/KOH). The sandwiching of carbon between the MoS 2 nanosheets increased the distance between the layers of MoS 2 and exposed more Mo sites, resulting in superior catalytic performance compared with that of bulk MoS 2 catalyst. The active hydrogen (H*) generated from N 2 H 4 could directly transfer to the –NO 2 groups of nitrobenzene to form aniline followed by N 2 emission, which was confirmed by detecting the gas emission with mass spectrometry during the decomposition of hydrazine or the co-existence of nitrobenzene and hydrazine.
Cheng Feng,Hai-Yan Zhang,Ning-Zhao Shang,Shu-Tao Gao,Chun Wang
Graphene-Fe 3 O 4 nanocomposite (G-Fe 3 O 4 ) was synthesized by a chemical co-precipitation method which was used as an efficient catalyst for the reduction of nitroarenes with hydrazine hydrate. The method has been applied to a broad range of compounds with different properties and the yields were in the range of 75%–92%. The G-Fe 3 O 4 catalyst can be readily recovered and reused 5 times without significant loss of the catalytic activity.
危险品化学品经营许可证（带存储）