Nanoscale Pd/Fe bimetallic particles were synthesized with an efficient method to dechlorinate o-chlorophenol. The nanoscale Pd/Fe particles were determined by transmission electron microscopy and BET specific surface...Nanoscale Pd/Fe bimetallic particles were synthesized with an efficient method to dechlorinate o-chlorophenol. The nanoscale Pd/Fe particles were determined by transmission electron microscopy and BET specific surface area analysis. Most of the particles are in the size range of 20—100 nm. The BET specific surface area of synthesized nanoscale Pd/Fe particles is 12.4 m 2/g. In contrast, a commercially available fine iron powder(<100 mesh) has a specific surface area of 0.49 m 2/g. Batch studies demonstrated that the nanoscale particles can effectively dechlorinate o-chlorophenol. The dechlorination reaction takes place on the surface of synthesized nanoscale Pd/Fe bimetallic particles in a pseudo-first order reaction. The surface-area-normalized rate coefficients(k_ SA) are comparable to those reported in the literature for chlorinated ethenes. The observed reaction rate constants(k_ obs) are dominated by the mass fraction of Pd and the mass concentration of the nanoscale Pd/Fe particles.展开更多
Contact glow discharge electrolysis (CGDE) of o-chlorophenol (2-CP) was investigated under different pH, voltages and initial concentrations. And the mechanism of the oxidation was explored. The results suggested that...Contact glow discharge electrolysis (CGDE) of o-chlorophenol (2-CP) was investigated under different pH, voltages and initial concentrations. And the mechanism of the oxidation was explored. The results suggested that the degradation followed the first order kinetic law; Fe2+ had a remarkable catalytic effect on the removal rate of o-chloropenol. In the presence of Fe2+, 2-CP underwent an exhaustive degradation, from which the major intermediates included o-dihydroxybenze, p-hydroxybenze, p-benzoquione and carboxlic acids.展开更多
Transformation of chlorophenols by nanoscale bimetallic particles represents one of the latest innovative technologies for environmental remediation. Nanoscale Pd/Fe bimetallic particles were synthesized in the labora...Transformation of chlorophenols by nanoscale bimetallic particles represents one of the latest innovative technologies for environmental remediation. Nanoscale Pd/Fe bimetallic particles were synthesized in the laboratory for treatment of o-chlorophenol. Most of the nanoscale particles are in the size range of 20—100 nm. BET specific surface area of the nanoscale Pd/Fe particles is 12.4 m2/g. In comparison, a commercially available Fe powder(<100 mesh) has a specific surface area of just 0\^49 m2/g. Batch experiments demonstrated that the nanoscale Pd/Fe bimetallic particles can effectively dechlorinate o-chlorophenol. Dechlorination efficiency is affected by the mass fraction of Pd in the bimetal, nanoscale Pd/Fe mass concentration and mixing intensity.展开更多
Catalytic wet air oxidation (CWAO) of o-chlorophenol in wastewater was studied in a stainless steel autoclave using four different Fe catalysts in the temperature range of 100?200 °C. Experimental results showed ...Catalytic wet air oxidation (CWAO) of o-chlorophenol in wastewater was studied in a stainless steel autoclave using four different Fe catalysts in the temperature range of 100?200 °C. Experimental results showed that high rate of o-chlorophenol and CODCr (Chemical Oxygen Demand, mg/L) removal by CWAO was obtained at relatively low temperature and pressure. The catalysts Fe2(SO4)3, FeSO4, Fe2O3 and FeCl3 all exhibited high catalytic activity. More than 93.7% of the initial CODCr and nearly 100% of o-chlorophenol were removed at 150 °C after 150 min with FeSO4 as catalyst. The CWAO of o-chlorophenol was found to be pseudo-first order reaction with respect to o-chlorophenol, with activation energy of 75.56 kJ/mol in the temperature range of 100-175 °C.展开更多
A cobalt-based hydrotalcite-like compound was prepared using a constant-pH coprecipitation method.Cobalt-transition metal oxides(Co2XA10,X=Co,Mg,Ca and Ni)were investigated for the deep catalytic oxidation of o-chloro...A cobalt-based hydrotalcite-like compound was prepared using a constant-pH coprecipitation method.Cobalt-transition metal oxides(Co2XA10,X=Co,Mg,Ca and Ni)were investigated for the deep catalytic oxidation of o-chlorophenol as a typical heteroatom contaminant containing chlorine atoms.The partial substitution of Co by Mg,Ca or Ni in the mixed oxide can promote the catalytic oxidation of o-chlorophenol.The Co2MgA10 catalyst presented the best catalytic activity,and could maintain 90%o-chlorophenol conversion at 167.1℃,compared only 27%conversion for the Co3A10 catalyst.The results demonstrated that the high activity could be attributed to its increased low-temperature reducibility,rich active oxygen species and excellent oxygen mobility.In the existence of acid and base sites,catalysts with strong basicity also showed preferred activity.The organic by-products generated during the o-chlorophenol catalytic oxidation over Co2MgAlO catalyst included carbon tetrachloride,trichloroethylene,2,4-dichlorophenol,and 2,6-dichloro-p-benzoquinon,et al.This work provides a facile method for the preparation of Co-based composite oxide catalysts,which represent promising candidates for typical chlorinated and oxygenated volatile organic compounds.展开更多
文摘Nanoscale Pd/Fe bimetallic particles were synthesized with an efficient method to dechlorinate o-chlorophenol. The nanoscale Pd/Fe particles were determined by transmission electron microscopy and BET specific surface area analysis. Most of the particles are in the size range of 20—100 nm. The BET specific surface area of synthesized nanoscale Pd/Fe particles is 12.4 m 2/g. In contrast, a commercially available fine iron powder(<100 mesh) has a specific surface area of 0.49 m 2/g. Batch studies demonstrated that the nanoscale particles can effectively dechlorinate o-chlorophenol. The dechlorination reaction takes place on the surface of synthesized nanoscale Pd/Fe bimetallic particles in a pseudo-first order reaction. The surface-area-normalized rate coefficients(k_ SA) are comparable to those reported in the literature for chlorinated ethenes. The observed reaction rate constants(k_ obs) are dominated by the mass fraction of Pd and the mass concentration of the nanoscale Pd/Fe particles.
基金The project supported by the Key Project of Science and Technology from the Ministry of Education China (No. 00250) the project of KJCXGC-01 of Northwest Normal University, China
文摘Contact glow discharge electrolysis (CGDE) of o-chlorophenol (2-CP) was investigated under different pH, voltages and initial concentrations. And the mechanism of the oxidation was explored. The results suggested that the degradation followed the first order kinetic law; Fe2+ had a remarkable catalytic effect on the removal rate of o-chloropenol. In the presence of Fe2+, 2-CP underwent an exhaustive degradation, from which the major intermediates included o-dihydroxybenze, p-hydroxybenze, p-benzoquione and carboxlic acids.
文摘Transformation of chlorophenols by nanoscale bimetallic particles represents one of the latest innovative technologies for environmental remediation. Nanoscale Pd/Fe bimetallic particles were synthesized in the laboratory for treatment of o-chlorophenol. Most of the nanoscale particles are in the size range of 20—100 nm. BET specific surface area of the nanoscale Pd/Fe particles is 12.4 m2/g. In comparison, a commercially available Fe powder(<100 mesh) has a specific surface area of just 0\^49 m2/g. Batch experiments demonstrated that the nanoscale Pd/Fe bimetallic particles can effectively dechlorinate o-chlorophenol. Dechlorination efficiency is affected by the mass fraction of Pd in the bimetal, nanoscale Pd/Fe mass concentration and mixing intensity.
基金Project (No. 20407015) supported by the National Natural ScienceFoundation of China
文摘Catalytic wet air oxidation (CWAO) of o-chlorophenol in wastewater was studied in a stainless steel autoclave using four different Fe catalysts in the temperature range of 100?200 °C. Experimental results showed that high rate of o-chlorophenol and CODCr (Chemical Oxygen Demand, mg/L) removal by CWAO was obtained at relatively low temperature and pressure. The catalysts Fe2(SO4)3, FeSO4, Fe2O3 and FeCl3 all exhibited high catalytic activity. More than 93.7% of the initial CODCr and nearly 100% of o-chlorophenol were removed at 150 °C after 150 min with FeSO4 as catalyst. The CWAO of o-chlorophenol was found to be pseudo-first order reaction with respect to o-chlorophenol, with activation energy of 75.56 kJ/mol in the temperature range of 100-175 °C.
基金This work is financially supported by the National Natural Science Foundation of China(Grant Nos.21677160 and 21477149)Beijing Municipal Science&Technology Commission(Nos.Z181100000118003 and Z 181100005418011).
文摘A cobalt-based hydrotalcite-like compound was prepared using a constant-pH coprecipitation method.Cobalt-transition metal oxides(Co2XA10,X=Co,Mg,Ca and Ni)were investigated for the deep catalytic oxidation of o-chlorophenol as a typical heteroatom contaminant containing chlorine atoms.The partial substitution of Co by Mg,Ca or Ni in the mixed oxide can promote the catalytic oxidation of o-chlorophenol.The Co2MgA10 catalyst presented the best catalytic activity,and could maintain 90%o-chlorophenol conversion at 167.1℃,compared only 27%conversion for the Co3A10 catalyst.The results demonstrated that the high activity could be attributed to its increased low-temperature reducibility,rich active oxygen species and excellent oxygen mobility.In the existence of acid and base sites,catalysts with strong basicity also showed preferred activity.The organic by-products generated during the o-chlorophenol catalytic oxidation over Co2MgAlO catalyst included carbon tetrachloride,trichloroethylene,2,4-dichlorophenol,and 2,6-dichloro-p-benzoquinon,et al.This work provides a facile method for the preparation of Co-based composite oxide catalysts,which represent promising candidates for typical chlorinated and oxygenated volatile organic compounds.
