A novel selective catalytic reduction(SCR)catalyst with high catalytic activity on chloroaromatic organics at lower temperatures(160-180℃)is critical for municipal solid waste incineration(MSWI)plants.This study prep...A novel selective catalytic reduction(SCR)catalyst with high catalytic activity on chloroaromatic organics at lower temperatures(160-180℃)is critical for municipal solid waste incineration(MSWI)plants.This study prepares a series of honeycomb-type VO_(x)/TiO_(2) catalysts and finally develops a new low-temperature catalyst with high catalytic activity in eliminating chloroaromatic organics.Based on the conversion efficiency(CE)of 1,2-dichlorobenzene(1,2-DCB)and CO_(2) selectivity,the optimal VO_(x) content of 4.06%(in weight)in VO_(x)/TiO_(2) catalyst is first confirmed.By modifying CeO_(x) and WO_(x),a novel honeycomb-type catalyst of VO_(x)-CeO_(x)-WO_(x)/TiO_(2) achieves the highest CE(93.1%-93.6%)and CO_(2) selectivity(40.9%-60.7%)at 150-200℃.It was found that the CeO_(x) and WO_(x) can improve the catalytic activity by enriching the surface content of V and O,increasing the proportion of V5+and Osurf,enlarging the supply source of reactive oxygen species and their storage capacity,and accelerating the redox cycle of VO_(x),CeO_(x),WO_(x),and reactive oxygen species.This study can guide the development of monolithic low-temperature catalysts with high catalytic activity in eliminating chloroaromatic organics in MSWI flue gas.展开更多
Industrial-use VOx-based catalysts usually have a higher active temperature window (>250-300℃),which becomes a“bottleneck”for the practical application of PCDD/Fs catalytic degradation technology.In this work,VO...Industrial-use VOx-based catalysts usually have a higher active temperature window (>250-300℃),which becomes a“bottleneck”for the practical application of PCDD/Fs catalytic degradation technology.In this work,VO_(x)-FeO_(x)/TiO_(2) catalyst prepared via mechanochemically method was investigated for the catalytic removal of PCDD/Fs.The removal efficiency of 1,2-DCBz,pure PCDD/Fs gas generated in the lab,PCDD/Fs from actual fue gas,long-term were studied,and the degradation mechanism was explored using FTIR and TOFMS.The degradation efficiency of 1,2-DCBz and PCDD/Fs on VO_(x)-FeO_(x)/TiO_(2) were higher than that of VO_(x)/TiO_(2)catalyst,and the optimal FeOx addition ratio was 3 wt.%.The characterization results show that the addition of FeOx can effectively improve the pore structure,surface acidity,and VOx dispersion of the catalyst,thus contributing to increasing the V^(5+)content and surface-active oxygen,which is conducive to the improvement of adsorption and redox performance of the catalyst.Under the actual MSWI (municipal solid waste incineration)fue gas,the PCDD/Fs removal efficiency over VTi-3Fe-MC maintained long-term stability,higher than 85%for 240 min.This result was not significantly reduced compared with the data obtained in the laboratory.According to the analysis results of intermediate products by FTIR and GC-TOFMS,it can be inferred that the epoxidation fracture of benzene ring is the rate-limiting step of dioxin catalytic degradation reaction.This work gives an in-depth view into the PCDD/Fs removal over VO_(x)-FeO_(x)/TiO_(2) catalysts and could provide guidelines for the rational design of reliable catalysts for industrial applications.展开更多
Multifunctional photocatalytic and thermochromic composites consisting of fluorine-doped vanadium dioxide(F-VO_(2))and niobium-doped TiO_(2)(NTO)were prepared by a simple physical mixing.The composites exhibited a hig...Multifunctional photocatalytic and thermochromic composites consisting of fluorine-doped vanadium dioxide(F-VO_(2))and niobium-doped TiO_(2)(NTO)were prepared by a simple physical mixing.The composites exhibited a higher thermochromic activity and nitrogen oxide(NO_(x))decomposition activity than that of pristine VO_(2)/NTO.Both VO_(2) and NTO materials were synthesized using an environmentally friendly soft chemical solvothermal/hydrothermal process,which produced NTO nanoparticles with a controllable morphology and particle size by changing the ratio of ethanol and acetic acid sol-vent.F-VO_(2)/NTO showed a better multifunctionality of thermochromic and photocatalytic activities than those of VO_(2)/NTO samples.The coexistence coating films showed a better effect on thermochromic and deNO_(x)(NO_(x) reduction)activity than those of double-sided films for F-VO_(2)/NTO samples.The best thermochromic and photocatalytic activities obtained from sample F-VO_(2)/NTO 60 showed the ΔT_(1500 nm)[difference of transmittance(ΔT)at the wavelength of 1500 nm under 25°C and 95°C]of up to 29.5%and deNO_(x) activity of up to 40%at λ>290 nm under mercury lamp irradiation.The use of F-VO_(2)/NTO coexistence coating films showed the appropriateness for multifunctional materials.展开更多
基金supported by the National Key Research and Development Program of China (No.2020YFC1910100).
文摘A novel selective catalytic reduction(SCR)catalyst with high catalytic activity on chloroaromatic organics at lower temperatures(160-180℃)is critical for municipal solid waste incineration(MSWI)plants.This study prepares a series of honeycomb-type VO_(x)/TiO_(2) catalysts and finally develops a new low-temperature catalyst with high catalytic activity in eliminating chloroaromatic organics.Based on the conversion efficiency(CE)of 1,2-dichlorobenzene(1,2-DCB)and CO_(2) selectivity,the optimal VO_(x) content of 4.06%(in weight)in VO_(x)/TiO_(2) catalyst is first confirmed.By modifying CeO_(x) and WO_(x),a novel honeycomb-type catalyst of VO_(x)-CeO_(x)-WO_(x)/TiO_(2) achieves the highest CE(93.1%-93.6%)and CO_(2) selectivity(40.9%-60.7%)at 150-200℃.It was found that the CeO_(x) and WO_(x) can improve the catalytic activity by enriching the surface content of V and O,increasing the proportion of V5+and Osurf,enlarging the supply source of reactive oxygen species and their storage capacity,and accelerating the redox cycle of VO_(x),CeO_(x),WO_(x),and reactive oxygen species.This study can guide the development of monolithic low-temperature catalysts with high catalytic activity in eliminating chloroaromatic organics in MSWI flue gas.
基金supported by the Natural Science Foundation of Zhejiang Province (No. LY21E060007)the National Natural Science Foundation of China (No. 52006191)。
文摘Industrial-use VOx-based catalysts usually have a higher active temperature window (>250-300℃),which becomes a“bottleneck”for the practical application of PCDD/Fs catalytic degradation technology.In this work,VO_(x)-FeO_(x)/TiO_(2) catalyst prepared via mechanochemically method was investigated for the catalytic removal of PCDD/Fs.The removal efficiency of 1,2-DCBz,pure PCDD/Fs gas generated in the lab,PCDD/Fs from actual fue gas,long-term were studied,and the degradation mechanism was explored using FTIR and TOFMS.The degradation efficiency of 1,2-DCBz and PCDD/Fs on VO_(x)-FeO_(x)/TiO_(2) were higher than that of VO_(x)/TiO_(2)catalyst,and the optimal FeOx addition ratio was 3 wt.%.The characterization results show that the addition of FeOx can effectively improve the pore structure,surface acidity,and VOx dispersion of the catalyst,thus contributing to increasing the V^(5+)content and surface-active oxygen,which is conducive to the improvement of adsorption and redox performance of the catalyst.Under the actual MSWI (municipal solid waste incineration)fue gas,the PCDD/Fs removal efficiency over VTi-3Fe-MC maintained long-term stability,higher than 85%for 240 min.This result was not significantly reduced compared with the data obtained in the laboratory.According to the analysis results of intermediate products by FTIR and GC-TOFMS,it can be inferred that the epoxidation fracture of benzene ring is the rate-limiting step of dioxin catalytic degradation reaction.This work gives an in-depth view into the PCDD/Fs removal over VO_(x)-FeO_(x)/TiO_(2) catalysts and could provide guidelines for the rational design of reliable catalysts for industrial applications.
基金This research was financially supported by the JSPS KAKENHI[Grant-in-Aid for Scientific Research on Innovative Areas“Mixed Anion”(Grant No.16H06439)]the Cooperative Research Program of“Network Joint Research Center for Materials and Devices”the Dynamic Alliance for Open Innovations Bridging Human,Environment,and Materials.
文摘Multifunctional photocatalytic and thermochromic composites consisting of fluorine-doped vanadium dioxide(F-VO_(2))and niobium-doped TiO_(2)(NTO)were prepared by a simple physical mixing.The composites exhibited a higher thermochromic activity and nitrogen oxide(NO_(x))decomposition activity than that of pristine VO_(2)/NTO.Both VO_(2) and NTO materials were synthesized using an environmentally friendly soft chemical solvothermal/hydrothermal process,which produced NTO nanoparticles with a controllable morphology and particle size by changing the ratio of ethanol and acetic acid sol-vent.F-VO_(2)/NTO showed a better multifunctionality of thermochromic and photocatalytic activities than those of VO_(2)/NTO samples.The coexistence coating films showed a better effect on thermochromic and deNO_(x)(NO_(x) reduction)activity than those of double-sided films for F-VO_(2)/NTO samples.The best thermochromic and photocatalytic activities obtained from sample F-VO_(2)/NTO 60 showed the ΔT_(1500 nm)[difference of transmittance(ΔT)at the wavelength of 1500 nm under 25°C and 95°C]of up to 29.5%and deNO_(x) activity of up to 40%at λ>290 nm under mercury lamp irradiation.The use of F-VO_(2)/NTO coexistence coating films showed the appropriateness for multifunctional materials.
