In order to study their synergistic catalytic effects in toluene degradation, CuMn2O4/HTS-1(HTS-1 was a titanium silicon molecular sieve), Cu0.7Mn2Y0.3Ox/HTS-1 and Cu0.7Mn2Ce0.3Ox/HTS-1 catalysts were prepared by the ...In order to study their synergistic catalytic effects in toluene degradation, CuMn2O4/HTS-1(HTS-1 was a titanium silicon molecular sieve), Cu0.7Mn2Y0.3Ox/HTS-1 and Cu0.7Mn2Ce0.3Ox/HTS-1 catalysts were prepared by the impregnation method.The textural properties, redox properties and acidity of the catalysts were characterized by X-ray diffractometer(XRD),transmission electron microscopy(TEM), scanning electron microscopy(SEM), H2 temperature-programmed reduction(H2-TPR), X-ray photoelectron spectroscopy(XPS),frustrated total internal reflection(FT-IR), ammonium temperature-programmed desorption(NH3-TPD) and pyridine adsorption internal reflection(Py-IR) measurements.The potential roles of Lewis acid sites(activating dioxygen) were discussed, and the experimental results indicated that the most efficient route for toluene degradation over Cu0.7Mn2Ce0.3Ox/HTS-1(toluene conversion rate of 90%(T99) = 295℃) was ascribed to regulation of the synergistic effects of redox properties(activating molecular toluene) and Lewis acid sites(activating dioxygen).The Mars–Van–Krevelen(MVK) model was adopted to describe the reaction process of toluene oxidation, which gave an in-depth view into the toluene degradation over CuMn2O4/HTS-1, Cu0.7Mn2Y0.3Ox/HTS-1 and Cu0.7Mn2Ce0.3Ox/HTS-1.In addition, the synergistic effects between redox properties and Lewis acid sites were studied in detail.展开更多
Atomic surface engineering for nanostructures significantly contributes to the enhancement of electrocatalysis for a given chemical reaction.However,exploring a facile method to elaborately regulate surfaces at atomic...Atomic surface engineering for nanostructures significantly contributes to the enhancement of electrocatalysis for a given chemical reaction.However,exploring a facile method to elaborately regulate surfaces at atomic scale remains a grand challenge.Herein,we report the construction of atomically rough surfaces(ARSs)on Au-based binary alloys through a novel and controllable gold(Au)-catalyzed strategy,which involves the first synthesis of Au-based bimetallic nanoalloys,i.e.,AuPd and AuAg,and subsequent reduction of another metal ions(Pt,Pd,or Ag)initiated by Au sites on the alloy particle surfaces.By combining ARSs with low-coordinated atoms with ligand effect induced by vicinal Au atoms,the as-prepared ARSs exhibit good activity and durability toward ethanol oxidation reaction(EOR)in an alkaline medium.In particular,the Pd-Pt ARSs on the AuPd alloy particle surface(denoted as AuPd-Pt)exhibit the highest electrocatalytic EOR performance in terms of both specific activity(14.9 mA cm^(–2))and mass activity(28.5 A mg^(–1)),surpassing those of their AuPd alloy counterparts,commercial Pd/C catalyst,and most Pd-based electrocatalysts reported recently.In situ Fourier transform infrared(FTIR)spectroscopy reveals that the EOR process on the Pd-Pt ARSs strongly prefers incomplete oxidation,which is further authenticated by the density functional theory(DFT)calculations.展开更多
We report Q-switched and mode-locked erbium-doped all-fiber lasers using ternary ReS_(2(1-x))Se_(2x) as saturable absorbers(SAs). The modulation depth and saturable intensity of the film SA are 1.8% and 0.046 MW∕cm2....We report Q-switched and mode-locked erbium-doped all-fiber lasers using ternary ReS_(2(1-x))Se_(2x) as saturable absorbers(SAs). The modulation depth and saturable intensity of the film SA are 1.8% and 0.046 MW∕cm2.In Q-switched mechanism output, the pulse was centered at 1531.1 nm with maximum pulse energy and minimum pulse width of 28.29 nJ and 1.07 μs, respectively. In mode-locked operation, the pulse was centered at1561.15 nm with pulse width of 888 fs, repetition rate of 2.95 MHz, and maximum pulse energy of 0.275 nJ. To the best of our knowledge, this is the first report on the mode-locked Er^(3+)-doped fiber laser using ternary transition metal dichalcogenides. This work suggests prospective 2 D-material SAs can be widely used in versatile fields due to their attractive optoelectronic and tunable energy bandgap properties.展开更多
基金supported by the Ministry of Education Blue Fire Program(No.CXZJH201717)Shijiazhuang Science and Technology Department(Nos.181240243A and 191240273A).
文摘In order to study their synergistic catalytic effects in toluene degradation, CuMn2O4/HTS-1(HTS-1 was a titanium silicon molecular sieve), Cu0.7Mn2Y0.3Ox/HTS-1 and Cu0.7Mn2Ce0.3Ox/HTS-1 catalysts were prepared by the impregnation method.The textural properties, redox properties and acidity of the catalysts were characterized by X-ray diffractometer(XRD),transmission electron microscopy(TEM), scanning electron microscopy(SEM), H2 temperature-programmed reduction(H2-TPR), X-ray photoelectron spectroscopy(XPS),frustrated total internal reflection(FT-IR), ammonium temperature-programmed desorption(NH3-TPD) and pyridine adsorption internal reflection(Py-IR) measurements.The potential roles of Lewis acid sites(activating dioxygen) were discussed, and the experimental results indicated that the most efficient route for toluene degradation over Cu0.7Mn2Ce0.3Ox/HTS-1(toluene conversion rate of 90%(T99) = 295℃) was ascribed to regulation of the synergistic effects of redox properties(activating molecular toluene) and Lewis acid sites(activating dioxygen).The Mars–Van–Krevelen(MVK) model was adopted to describe the reaction process of toluene oxidation, which gave an in-depth view into the toluene degradation over CuMn2O4/HTS-1, Cu0.7Mn2Y0.3Ox/HTS-1 and Cu0.7Mn2Ce0.3Ox/HTS-1.In addition, the synergistic effects between redox properties and Lewis acid sites were studied in detail.
基金supported by the National Natural Science Foundation of China(22272179,22075290,and 42307326)the Natural Science Foundation of Hebei Province(E2021203005 and B2021203016)+2 种基金Department of Education of Hebei Province(BJ2021042)Chinese Academy of Sciences Project for Young Scientists in Basic Research(YSBR-044)State Key Laboratory of Mesoscience and Engineering,Institute of Process Engineering,Chinese Academy of Sciences(MESO-23-A06 and MESO-24-A01).
文摘Atomic surface engineering for nanostructures significantly contributes to the enhancement of electrocatalysis for a given chemical reaction.However,exploring a facile method to elaborately regulate surfaces at atomic scale remains a grand challenge.Herein,we report the construction of atomically rough surfaces(ARSs)on Au-based binary alloys through a novel and controllable gold(Au)-catalyzed strategy,which involves the first synthesis of Au-based bimetallic nanoalloys,i.e.,AuPd and AuAg,and subsequent reduction of another metal ions(Pt,Pd,or Ag)initiated by Au sites on the alloy particle surfaces.By combining ARSs with low-coordinated atoms with ligand effect induced by vicinal Au atoms,the as-prepared ARSs exhibit good activity and durability toward ethanol oxidation reaction(EOR)in an alkaline medium.In particular,the Pd-Pt ARSs on the AuPd alloy particle surface(denoted as AuPd-Pt)exhibit the highest electrocatalytic EOR performance in terms of both specific activity(14.9 mA cm^(–2))and mass activity(28.5 A mg^(–1)),surpassing those of their AuPd alloy counterparts,commercial Pd/C catalyst,and most Pd-based electrocatalysts reported recently.In situ Fourier transform infrared(FTIR)spectroscopy reveals that the EOR process on the Pd-Pt ARSs strongly prefers incomplete oxidation,which is further authenticated by the density functional theory(DFT)calculations.
基金National Key R&D Program of China(2018YFB1107200)National Natural Science Foundation of China(NSFC)(61675158,21673058)+1 种基金Chinese Academy of Sciences Key Project(CAS Key Project)(QYZDBSSW-SYS031)Chinese Academy of Sciences(CAS)(XDB30000000)
文摘We report Q-switched and mode-locked erbium-doped all-fiber lasers using ternary ReS_(2(1-x))Se_(2x) as saturable absorbers(SAs). The modulation depth and saturable intensity of the film SA are 1.8% and 0.046 MW∕cm2.In Q-switched mechanism output, the pulse was centered at 1531.1 nm with maximum pulse energy and minimum pulse width of 28.29 nJ and 1.07 μs, respectively. In mode-locked operation, the pulse was centered at1561.15 nm with pulse width of 888 fs, repetition rate of 2.95 MHz, and maximum pulse energy of 0.275 nJ. To the best of our knowledge, this is the first report on the mode-locked Er^(3+)-doped fiber laser using ternary transition metal dichalcogenides. This work suggests prospective 2 D-material SAs can be widely used in versatile fields due to their attractive optoelectronic and tunable energy bandgap properties.
