Synergistic effect of FeVO_4 withα-Fe_2O_3 was found in Fe-V-O catalyst,which was responsible for the high apparent formation rate（A.F.R.） of benzaldehyde in liquid phase oxidation of toluene by hydrogen peroxide.T...Synergistic effect of FeVO_4 withα-Fe_2O_3 was found in Fe-V-O catalyst,which was responsible for the high apparent formation rate（A.F.R.） of benzaldehyde in liquid phase oxidation of toluene by hydrogen peroxide.The synergistic effect might create VO_πspecies as active sites;moreover,it improved the reducibility and the reactivity of Fe-V-O catalyst.In order to gain the high A.F.R. of benzaldehyde,the catalyst should have the moderate reducibihty.展开更多
The Fe_(1−x)Ni_(x)VO_(4)(x=0,0.05,0.10,and 0.20)nanoparticles in this work were successfully synthesized via a co-precipitation method.The structural,magnetic and electrochemical properties of the prepared Fe_(1−x)Ni_...The Fe_(1−x)Ni_(x)VO_(4)(x=0,0.05,0.10,and 0.20)nanoparticles in this work were successfully synthesized via a co-precipitation method.The structural,magnetic and electrochemical properties of the prepared Fe_(1−x)Ni_(x)VO_(4) nanoparticles were studied as a function of Ni content.The experimental results show that the prepared Ni-doped FeVO_(4) samples have a triclinic structure.Scanning electron microscopy(SEM)images reveal a decrease in average nanoparticle size with increasing Ni content,leading to an enhancement in both specific surface area and magnetization values.X-ray absorption near edge structure(XANES)analysis confirms the substitution of Ni^(2+)ions into Fe^(3+)sites.The magnetic investigation reveals that Ni-doped FeVO_(4) exhibits weak ferromagnetic behavior at room temperature,in contrast to the antiferromagnetic behavior observed in the undoped FeVO_(4).Electrochemical studies demonstrate that the Fe_(0.95)Ni_(0.05)VO_(4) electrode achieves the highest specific capacitance of 334.05 F·g^(−1) at a current density of 1 A·g^(−1),which is attributed to its smallest average pore diameter.In addition,the enhanced specific surface of the Fe_(0.8)Ni_(0.2)VO_(4) electrode is responsible for its outstanding cyclic stability.Overall,our results suggest that the magnetic and electrochemical properties of FeVO_(4) nanoparticles could be effectively tuned by varying Ni doping contents.展开更多
Developing deNO_(x)catalysts with lower activity temperatures range significantly reduces NH_(3)selective catalytic reduction(SCR)operating costs for low-temperature industrial flue gases.Herein,a novel FeVO_(4)/CeO_(...Developing deNO_(x)catalysts with lower activity temperatures range significantly reduces NH_(3)selective catalytic reduction(SCR)operating costs for low-temperature industrial flue gases.Herein,a novel FeVO_(4)/CeO_(2)catalyst with great low-temperature NH_(3)-SCR and nitrogen selectivity was synthesized using a dipping method.Characterization techniques such as X-ray diffraction,Raman spectroscopy,specific surface and porosity analysis,H2 temperature-programmed reduction,NH_(3)temperature-programmed desorption,X-ray photoelectron spectroscopy,and the in situ diffused reflectance infrared Fourier transform spectroscopy were used to investigate the catalytic mechanism.An appropriate addition for FeVO_(4)in the catalyst was 5 wt.%from the results,and the active substance content reached the maximum dispersal capacity of the carrier.The NO_(x)conversion exceeded 90%,and the nitrogen selectivity was more than 98%over this catalyst at 200–350℃.The activity was kept at 88%after 7.5 h of reaction at 200℃ for 7.5 h in 35 mg m^(-3)SO_(2)gas.The remarkable deNO_(x)activity,nitrogen selectivity,and sulphur resistance performances are attributed to the low redox temperature,the abundance of medium-strong acid and strong acid sites,the sufficient adsorbed oxygen,and the superior Fe^(2+)content on the surface.The Langmuir–Hinshelwood mechanism was observed on the FeVO_(4)/CeO_(2)catalyst in the NH_(3)selective catalytic reduction of NO_(x).展开更多
基金supported by Ministry of Education(NoNCET-10-878,20096101120018,2009-37th of SRFROCS)Shaanxi Province(No2009ZDKG-70,09JK793)+1 种基金Northwest University(NoPR09005,10YSY08)State Key Lab for SSPC(2009)
文摘Synergistic effect of FeVO_4 withα-Fe_2O_3 was found in Fe-V-O catalyst,which was responsible for the high apparent formation rate（A.F.R.） of benzaldehyde in liquid phase oxidation of toluene by hydrogen peroxide.The synergistic effect might create VO_πspecies as active sites;moreover,it improved the reducibility and the reactivity of Fe-V-O catalyst.In order to gain the high A.F.R. of benzaldehyde,the catalyst should have the moderate reducibihty.
文摘The Fe_(1−x)Ni_(x)VO_(4)(x=0,0.05,0.10,and 0.20)nanoparticles in this work were successfully synthesized via a co-precipitation method.The structural,magnetic and electrochemical properties of the prepared Fe_(1−x)Ni_(x)VO_(4) nanoparticles were studied as a function of Ni content.The experimental results show that the prepared Ni-doped FeVO_(4) samples have a triclinic structure.Scanning electron microscopy(SEM)images reveal a decrease in average nanoparticle size with increasing Ni content,leading to an enhancement in both specific surface area and magnetization values.X-ray absorption near edge structure(XANES)analysis confirms the substitution of Ni^(2+)ions into Fe^(3+)sites.The magnetic investigation reveals that Ni-doped FeVO_(4) exhibits weak ferromagnetic behavior at room temperature,in contrast to the antiferromagnetic behavior observed in the undoped FeVO_(4).Electrochemical studies demonstrate that the Fe_(0.95)Ni_(0.05)VO_(4) electrode achieves the highest specific capacitance of 334.05 F·g^(−1) at a current density of 1 A·g^(−1),which is attributed to its smallest average pore diameter.In addition,the enhanced specific surface of the Fe_(0.8)Ni_(0.2)VO_(4) electrode is responsible for its outstanding cyclic stability.Overall,our results suggest that the magnetic and electrochemical properties of FeVO_(4) nanoparticles could be effectively tuned by varying Ni doping contents.
基金supported by the National Natural Science Foundation of China(52204332 and 52174290)the Outstanding Youth Fund of Anhui Province(2208085J19)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(21KJB450002).
文摘Developing deNO_(x)catalysts with lower activity temperatures range significantly reduces NH_(3)selective catalytic reduction(SCR)operating costs for low-temperature industrial flue gases.Herein,a novel FeVO_(4)/CeO_(2)catalyst with great low-temperature NH_(3)-SCR and nitrogen selectivity was synthesized using a dipping method.Characterization techniques such as X-ray diffraction,Raman spectroscopy,specific surface and porosity analysis,H2 temperature-programmed reduction,NH_(3)temperature-programmed desorption,X-ray photoelectron spectroscopy,and the in situ diffused reflectance infrared Fourier transform spectroscopy were used to investigate the catalytic mechanism.An appropriate addition for FeVO_(4)in the catalyst was 5 wt.%from the results,and the active substance content reached the maximum dispersal capacity of the carrier.The NO_(x)conversion exceeded 90%,and the nitrogen selectivity was more than 98%over this catalyst at 200–350℃.The activity was kept at 88%after 7.5 h of reaction at 200℃ for 7.5 h in 35 mg m^(-3)SO_(2)gas.The remarkable deNO_(x)activity,nitrogen selectivity,and sulphur resistance performances are attributed to the low redox temperature,the abundance of medium-strong acid and strong acid sites,the sufficient adsorbed oxygen,and the superior Fe^(2+)content on the surface.The Langmuir–Hinshelwood mechanism was observed on the FeVO_(4)/CeO_(2)catalyst in the NH_(3)selective catalytic reduction of NO_(x).
