Catalysts
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2021
·Vol. 11
·期 5
·543
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IF 4.146
Zechen Liang,Mingkai Zhang,Sai Zhang,Yongquan Qu
Selective hydrogenation of halonitrobenzenes into haloanilines represents a green process to replace the environmentally unfriendly non-catalytic chemical reduction process in industry. However, this transformation often suffers from serious dehalogenation due to the easy break of carbon-halogen bonds on metal surfaces. Modulations of the electronic structure of the supported Pd nanoparticles on Lewis-basic layered double hydroxides have been demonstrated to promote catalytic activity and selectivity for hydrogenation of halonitrobenzenes into haloanilines. Mechanism studies suggest that Pd with the enhanced electron density not only improves the capability for hydrogen activation, but also generates the partially negative-charged hydrogen species to suppress the electrophilic attack on the carbon-halogen bond and avoid the dehalogenation.Keywords:Pd nanoparticles;hydrogenation;halonitrobenzenes;haloanilines
研究领域:
化学
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催化材料科学
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产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
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2023
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IF 6.7
Hongbo Yu,Shuibo Wang,Lin Zhu,Chunzheng Wu
Pt nanocatalysts exhibits superior activity towards the hydrogenation reaction of halonitrobenzenes (HNBs), but the selectivity to the valuable product haloanilines (HANs) is always poor due to the unavoidable dehalogenation process. In this study, we find that coating a thin Sn layer on Pt nanoparticles (NPs) could improve not only the hydrogenation activity but also the selectivity to HANs. These core–shell structured Pt@Sn NPs with different Sn shell thickness were synthesized by one-pot reduction, and their catalytic performance in the hydrogenation reaction of p -chloronitrobenzene to p -chloroaniline could be effectively regulated by the Pt/Sn ratio. The catalyst with a Pt/Sn ratio of 5/1 achieved the highest p -chloronitrobenzene conversion (96.5 %) and excellent selectivity to p -chloroaniline (97.9 %). The kinetic study and H 2 -TPD analysis indicated that the Sn species on Pt could facilitate the adsorption of p -chloronitrobenzene and the dissociation of H 2 . The designed Pt@Sn core–shell nanocatalysts are applicable to a wide range of hydrogenation reactions.
研究领域:
化学工程
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催化科学
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产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
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2022
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IF 11.357
Di Zhang,Tom Bond,Yang Pan,Mingli Li,Jiayi Luo,Rong Xiao,Wenhai Chu
Identifying disinfection byproducts (DBPs) with high health risk is an unresolved challenge. In this study, six members of a new class of aromatic nitrogenous DBPs─2-chloroaniline, 2-bromoaniline, 2,4-dichloroaniline, 2-chloro-4-bromoaniline, 4-chloro-3-nitroaniline, and 2-chloro-4-nitroaniline─are reported as DBPs in drinking water for the first time. Haloanilines completely degraded within 1 h in the presence of chlorine (1 mg/L), while about 20% remained in the presence of chloramine (1 mg/L) after 120 h. Haloanilines showed high stability in the absence of disinfectants, with <30% degradation at pH 5–9 over 120 h. Eight haloanilines were determined in chloraminated finished water and tap water at total concentrations of up to 443 ng/L. The most abundant was 2-bromoaniline, with a median concentration of 104 ng/L. The cytotoxicity of eight haloanilines and regulated trichloromethane and dichloroacetic acid (DCAA) was evaluated using Hep G2 cell assay. The EC50 values of eight haloanilines were 1–2 orders of magnitude lower than those of the regulated DBPs. The lowest toxic concentration of 2-chloro-4-nitroaniline was 1 μM, 500 times lower than that of DCAA. The formation and control of haloanilines in drinking water warrant further investigation.
研究领域:
环境科学
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水处理
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毒理学
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公共卫生
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产品关联
DOI
PubMed
高影响因子
CATALYSIS LETTERS
·
2023
·Vol. 153
·期 12
·3569-3580
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IF 2.8
Lin Shanshan,Liu Jianguo,Ma Longlong
Aniline is a group of important platform molecules that has been widely used in the synthesis of other high-value chemicals and pharmaceutical products. How to produce high-value anilines as the high-value chemical intermediates more efficiently and environmentally has always been a research topic in the industry. Catalytic hydrogenation is an environmentally friendly method for preparing halogenated anilines. Traditional noble metal catalysts face the problems of cost and noble metals residue. To improve the purity of the product as well as the activity and recyclability of the catalyst, we prepared a Pd/Fe magnetic bimetallic catalyst supported on N-doped carbon materials to reduce nitrobenzene to aniline under mild conditions. The catalyst has a low Pd loading of 2.35%. And the prepared bimetallic Pd/Fe@N/C catalyst showed excellent catalytic reactivity with the nitrobenzene conversion rate of 99%, and the aniline selectivity of 99% under mild reaction conditions of 0.8 MPa H 2 and 40 °C. A variety of halogenated and aliphatic nitro compounds were well tolerated and had been transformed to the corresponding target amine products with excellent selectivity. In addition, the novel N-doped graphene-encapsulated bimetallic magnetic Pd/Fe@N/C catalyst not only had magnetic physical properties, which was easy to separate, recover, and used for the recycling of the catalyst without metal leaching but also catalyzed highly selective reductive amination of aromatics was a green, economical and environmentally friendly reaction with the only by-product of H 2 O. Graphical Abstract
研究领域:
化学
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催化
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材料科学
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环境科学
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产品关联
DOI
PubMed
高影响因子
EUROPEAN JOURNAL OF MASS SPECTROMETRY
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2018
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IF 1
Shanshan Wang,Yuanyuan Cheng,Mengmeng Chen,Kezhi Jiang
Differentiation of the isomeric haloanilines still remains a challenging and necessary analytic task due to their identical retention time in chromatography and similar mass spectra. In this work, p-tosylation of haloanilines by reaction of haloanilines with p-toluenesulfonyl chloride resulted in the corresponding N-tosyl haloanilines. Fragmentation of protonated N-tosyl haloanilines in electrospray ionization tandem mass spectrometry (ESI-MS/MS) mainly resulted in tosyl cation, haloaniline radical cation, and halohydroxyaniline radical cation. The MS/MS of the three group isomeric derivatives showed significant difference in abundance distribution of these product ions, respectively. Theoretical calculations showed that the stability of the ion-neutral complex (INC) is a key factor influencing the relative intensity of the product ions. The three group isomeric derivatives were also separated by high performance liquid chromatograph (HPLC) at conventional conditions. p-Tosylation combined tandem MS (or HPLC) technique were carried out to realize the differentiation of isomeric haloanilines.
研究领域:
分析化学
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质谱学
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有机化学
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产品关联
DOI
PubMed
高影响因子
Nature Catalysis
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2021
·Vol. 4
·期 10
·840-849
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IF 41.813
Guan Qiaoqiao,Zhu Chuwei,Lin Yue,Vovk Evgeny I.,Zhou Xiaohong,Yang Yong,Yu Hancheng,Cao Lina,Wang Hengwei,Zhang Xiaohui,Liu Xinyu,Zhang Mengkai,Wei Shiqiang,Li Wei-Xue,Lu Junling
Particle size governs the geometric and electronic structure of metal nanoparticles (NPs), shaping their catalytic performance. However, size-dependent entanglement in the geometric and electronic structures often leads to a trade-off between activity and selectivity, limiting the optimization of the overall catalytic performance. Here we show that precisely controlled deposition of a platinum monolayer on large gold NPs breaks the activity–selectivity trade-off on particle size in platinum-catalysed chemoselective hydrogenation of halonitrobenzenes, resulting in a remarkable activity, along with a 99% selectivity for haloanilines under mild conditions. The high activity results from upshift of the platinum 5 d -band centre through platinum lattice expansion and ligand effect, whereas the high selectivity is caused by exposing more terrace sites on large particles. The geometric and electronic properties of bimetallic monolayer materials, distinct from monometallic NPs and alloys, constitute a promising platform for the rational design of metal catalysts with superior performance in hydrogenation reactions.
研究领域:
催化
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材料科学
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化学
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DOI
高影响因子
危险品化学品经营许可证（带存储）