95-57-8Relevant articles and documents
Pd supported on boron-doped mesoporous carbon as highly active catalyst for liquid phase catalytic hydrodechlorination of 2,4-dichlorophenol
Zhou, Juan,Wu, Ke,Wang, Wenjuan,Xu, Zhaoyi,Wan, Haiqin,Zheng, Shourong
, p. 336 - 343 (2014)
Palladium catalysts supported on both ordered mesoporous carbon (CMK-3) and boron-doped mesoporous carbon (B-CMK-3) were synthesized via the complexing-reduction method. These catalysts were characterized using X-ray diffraction, N2 adsorption-desorption, transmission electron microscopy, and X-ray photoelectron spectroscopy, and their catalytic performance was examined for the liquid phase catalytic hydrodechlorination (HDC) of 2,4-dichlorophenol. Characterization results showed that for B-CMK-3 boron was introduced into the framework of the mesoporous carbon. Pd supported on B-CMK-3 had a smaller average Pd particle size and higher Pd 2+/Pd0 ratio than that on CMK-3, although B-CMK-3 had slightly lower surface area and pore volume than CMK-3. For Pd/B-CMK-3, increasing Pd loading led to an increase in Pd particle size and a decrease in Pd2+/Pd0 ratio. The liquid phase catalytic HDC of 2,4-dichlorophenol over Pd/B-CMK-3 followed the Langmuir-Hinshelwood model, and the catalytic reaction proceeded in both stepwise and concerted pathways. The initial reaction rates of Pd(2.7)/B-CMK-3 and Pd(2.6)/CMK-3 were 0.608 and 0.207 M gCat-1 h-1, respectively, reflecting a much higher catalytic activity of Pd/B-CMK-3 than that of Pd/CMK-3. For Pd/B-CMK-3, increasing Pd loading from 1.6 to 2.7 wt.% led to an increase in the initial rate from 0.260 to 0.608 M gCat-1 h-1, but further increase of the loading to 3.9 wt.% resulted in a slight decrease in the catalytic activity.
Enhanced catalytic hydrodechlorination of 2,4-dichlorophenol over Pd catalysts supported on nitrogen-doped graphene
Zhou, Juan,Chen, Quanyuan,Han, Yuxiang,Zheng, Shourong
, p. 91363 - 91371 (2015)
Pd catalysts supported on graphene and N-doped graphene (GN-1, GN-2 and GN-3) with varied N-doping amounts were prepared using the deposition-precipitation method, and liquid phase catalytic hydrodechlorination (HDC) of 2,4-dichlorophenol (2,4-DCP) was investigated over these catalysts. The catalysts were characterized by X-ray diffraction, elementary analysis, N2 adsorption-desorption isotherms, transmission electron microscopy, and X-ray photoelectron spectroscopy. Characterization results showed that graphene could be successfully doped by N using the heat treatment method with melamine as precursor, and N doping amounts were determined to be 5.7, 8.6 and 11.3% for GN-1, GN-2 and GN-3, respectively. Additionally, Pd2+/Pd0 ratios and Pd dispersions in the Pd/GN catalysts were much higher than those in Pd/graphene. For a similar Pd loading, the Pd dispersion of Pd/GN first increased and then decreased with the increase of N-doping amount, and the highest Pd dispersion was observed on Pd(2.9)/GN-2. Accordingly, GN supported Pd catalysts exhibited much higher catalytic activities than Pd/graphene, the catalytic reaction first increased and then decreased slightly in activity with the increase of nitrogen doping amount, and the highest activity was identified on Pd(2.9)/GN-2. Moreover, the dechlorination of 2,4-DCP over supported Pd catalysts proceeded via both a stepwise and concerted pathway, and the concerted pathway became predominant upon N doping.
Photochemical transformations of 2, 6-dichlorophenol and 2-chlorophenol with superoxide ions in the atmospheric aqueous phase
Dong, Linchang,Hu, Shuheng,Lu, Jun,Peng, Shuchuan,Zhu, Chengzhu,Zhu, Mengyu
, (2022/04/03)
The possible photochemical transformation pathways of chlorophenols (2, 6-dichlorophenol and 2-chlorophenol) with superoxide anion radical (O2·?) were studied by steady-state irradiation and 355 nm laser flash photolysis technique. O
Catalyst-free rapid conversion of arylboronic acids to phenols under green condition
Dong, Zhenhua,Liu, Mengmeng,Pan, Hongguo
, (2021/09/06)
A catalyst-free and solvent-free method for the oxidative hydroxylation of aryl boronic acids to corresponding phenols with hydrogen peroxide as the oxidizing agent was developed. The reactions could be performed under green condition at room temperature within very short reaction time. 99% yield of phenol could be achieved in only 1 min. A series of different arenes substituted aryl boronic acids were further carried out in the hydroxylation reaction with excellent yield. It was worth nothing that the reaction could completed within 1 min in all cases in the presence of ethanol as co-solvent.