NiMnO3 perovskite catalysts supported on cordierite modified by CexZr（1-x）O2 coatings were prepared using impregnation and sol-gel methods for catalytic combustion of single/double component VOCs at different concen...NiMnO3 perovskite catalysts supported on cordierite modified by CexZr（1-x）O2 coatings were prepared using impregnation and sol-gel methods for catalytic combustion of single/double component VOCs at different concentrations and GHSV of 15,000 h^（-1）, which were characterized by BET, XRD, SEM, FT-IR, H2-TPR and O2-TPD. After coating modification, the specific surface area of catalysts is improved obviously.Among the catalysts, the Ce（0.75）Zr（0.25）O2 coating modified NiMnO3 catalyst exhibits the best catalytic activity for VOCs combustion with 95.6% conversion at 275 ℃ and has stable activity when catalyst is embalmed at 800 ℃. In addition, the catalyst also presents the excellent water-resistant and conversion stability over time-on-stream condition. The reason is that Ce（0.75）Zr（0.25）O2 coating can promote more lattice distortion and defects and smaller crystal size, which improve oxygen transfer capability and dispersion of active component.展开更多
Atomic layer deposition(ALD)attracts great attention nowadays due to its ability for designing and modifying catalytic systems at the molecular level.There are several reported review papers published recently discuss...Atomic layer deposition(ALD)attracts great attention nowadays due to its ability for designing and modifying catalytic systems at the molecular level.There are several reported review papers published recently discussing this technique in catalysis.However,the mechanism on how the deposited materials improve the catalyst stability and tune the reaction selectivity is still unclear.Herein,catalytic systems created via ALD on stepwise preparation and/or modification under self-limiting reaction conditions are summarized.The effects of deposited materials in terms of electronic/geometry modification over the catalytic nanoparticles(NPs)are discussed.These effects explain the mechanism of the catalytic stability improvement and the selectivity modification.The unique properties of ALD for designing new catalytic systems are further investigated for building up photocatalytic reaction nanobowls,tandem catalyst and bi-active-component metallic catalytic systems.展开更多
The Cu-Mn catalysts doped with different amounts of lanthanum（La） for water-gas shift reaction（WGSR） were prepared, and characterized by X-ray diffraction（XRD）, temperature-programmed reduction（TPR）, temperatu...The Cu-Mn catalysts doped with different amounts of lanthanum（La） for water-gas shift reaction（WGSR） were prepared, and characterized by X-ray diffraction（XRD）, temperature-programmed reduction（TPR）, temperature-programmed reduction of oxidized surfaces（s-TPR）, temperature-programmed desorption of CO_2（CO_2-TPD）, infrared spectrum（FT-IR） and X-ray photoelectron spectroscopy（XPS）. Catalytic activities were tested for a water-gas shift reaction. The results showed that the introduction of 0.5 mol.% La could significantly improve the catalyst activity for low-temperature shift reaction compared with the undoped catalyst, which might be from the introduction of La making the Cu and Mn components distribute uniformly and the synergistic effect between Cu and Mn increasing the dispersion of Cu on the surface of the catalyst. The apparent CuO phases besides Cu_（1.5）Mn_（1.5）O_4 were found in the samples with at least 3.0 mol.% La content, and the basic sites increased with the increasing of La contents at a decreased rate. With excessive La doping, La particles would aggregate and cover some active sites, resulting in that Mn could not effectively inhibit the gathering together and growing up of Cu crystalline grain, and decreased the dispersion of Cu on the surface, which resulted in the poor activity of the catalyst for WGSR.展开更多
Pd@Zr/Ce O2 core-shell catalyst prepared by hydrothermal method was applied in CO oxidation reaction, exhibiting high CO oxidation activity at low temperature.XRD（X-ray diffraction） analysis demonstrated that the re...Pd@Zr/Ce O2 core-shell catalyst prepared by hydrothermal method was applied in CO oxidation reaction, exhibiting high CO oxidation activity at low temperature.XRD（X-ray diffraction） analysis demonstrated that the remarkable enhancement of catalytic performance was found to depend on the presence of more oxygen vacancies in the core-shell structure, which contributed higher content of and ready release of active oxygen species at low temperature, confirmed by H2-TPR（temperature programed reduction） results.Interestingly, introducing a small amount of zirconium（0.5 wt.%） exhibited a significant improvement of catalytic activity because the introduction of Zr further improved the amount of crystal defects and promoted the migration of oxygen species.展开更多
The main results of hydrocracking of goudron under reduced pressure in the presence of a suspended catalyst have been analyzed. It was investigated the influence of pressure to hydrocracking process of goudron. It was...The main results of hydrocracking of goudron under reduced pressure in the presence of a suspended catalyst have been analyzed. It was investigated the influence of pressure to hydrocracking process of goudron. It was determined that with increasing from 0.5 to 4.0 MPa, the yield of light oil products increased from 47% to 58% mass.展开更多
Methanol steam reforming manifests great potential for generating hydrogen owing to its lower reaction temper-ature(200-300°C)and higher hydrogen/carbon ratio comparing with ethanol and methane reforming.In this ...Methanol steam reforming manifests great potential for generating hydrogen owing to its lower reaction temper-ature(200-300°C)and higher hydrogen/carbon ratio comparing with ethanol and methane reforming.In this case,methanol steam reforming is applied in various renewable energy systems to assist the energy conversion and improve the system efficiency.The performance of methanol steam reforming reaction strongly depends on the catalysts and reactor structure.In this paper,the development of the copper-based,the noble metal-based and the nanomaterial catalysts were summarized by analyzing the effects of different modification methods,which indicates that cutting the cost and simplifying the manufacturing process are the future goal of catalyst modifi-cation.Moreover,the reaction mechanism of different catalyst types was discussed.For the reactor performance,conventional,miniature,micro,and membrane reactors were discussed and compared,where conventional reac-tor with high CO tolerance is more suitable for industrial application while membrane reactor with high H 2 purity and compact structure is ideal for fuel cell technology.The integration of the methanol steam reforming system into renewable power systems was reviewed as well.Methanol steam reforming technology is of great potential in exhaust heat recovery,cogeneration system and other renewable energy field,where more comprehensive researches should be performed.展开更多
基金Project supported by the Science and Technology Department of Jiangsu Province(BE2016769)the Natural Science Foundation of China(51172107)+2 种基金Natural Science Foundation of the Jiangsu Higher Education Institutions of China(14KJB430014)Open fund by Jiangsu Engineering Technology Research Center of Environmental Cleaning Materials(KFK1503)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘NiMnO3 perovskite catalysts supported on cordierite modified by CexZr（1-x）O2 coatings were prepared using impregnation and sol-gel methods for catalytic combustion of single/double component VOCs at different concentrations and GHSV of 15,000 h^（-1）, which were characterized by BET, XRD, SEM, FT-IR, H2-TPR and O2-TPD. After coating modification, the specific surface area of catalysts is improved obviously.Among the catalysts, the Ce（0.75）Zr（0.25）O2 coating modified NiMnO3 catalyst exhibits the best catalytic activity for VOCs combustion with 95.6% conversion at 275 ℃ and has stable activity when catalyst is embalmed at 800 ℃. In addition, the catalyst also presents the excellent water-resistant and conversion stability over time-on-stream condition. The reason is that Ce（0.75）Zr（0.25）O2 coating can promote more lattice distortion and defects and smaller crystal size, which improve oxygen transfer capability and dispersion of active component.
基金supported by the U.S. Department of Energy, Office of Science, and Office of the Basic Energy Sciences, under Contract DE-AC-02-06CH11357~~
文摘Atomic layer deposition(ALD)attracts great attention nowadays due to its ability for designing and modifying catalytic systems at the molecular level.There are several reported review papers published recently discussing this technique in catalysis.However,the mechanism on how the deposited materials improve the catalyst stability and tune the reaction selectivity is still unclear.Herein,catalytic systems created via ALD on stepwise preparation and/or modification under self-limiting reaction conditions are summarized.The effects of deposited materials in terms of electronic/geometry modification over the catalytic nanoparticles(NPs)are discussed.These effects explain the mechanism of the catalytic stability improvement and the selectivity modification.The unique properties of ALD for designing new catalytic systems are further investigated for building up photocatalytic reaction nanobowls,tandem catalyst and bi-active-component metallic catalytic systems.
基金Project supported by the National Natural Science Foundation of China(21266017,21566028,21566029)Research Fund for the Doctoral Program of Higher Education of China(20111514110001)Inner Mongolia Natural Science Foundation(2014MS0220,2015BS0206)
文摘The Cu-Mn catalysts doped with different amounts of lanthanum（La） for water-gas shift reaction（WGSR） were prepared, and characterized by X-ray diffraction（XRD）, temperature-programmed reduction（TPR）, temperature-programmed reduction of oxidized surfaces（s-TPR）, temperature-programmed desorption of CO_2（CO_2-TPD）, infrared spectrum（FT-IR） and X-ray photoelectron spectroscopy（XPS）. Catalytic activities were tested for a water-gas shift reaction. The results showed that the introduction of 0.5 mol.% La could significantly improve the catalyst activity for low-temperature shift reaction compared with the undoped catalyst, which might be from the introduction of La making the Cu and Mn components distribute uniformly and the synergistic effect between Cu and Mn increasing the dispersion of Cu on the surface of the catalyst. The apparent CuO phases besides Cu_（1.5）Mn_（1.5）O_4 were found in the samples with at least 3.0 mol.% La content, and the basic sites increased with the increasing of La contents at a decreased rate. With excessive La doping, La particles would aggregate and cover some active sites, resulting in that Mn could not effectively inhibit the gathering together and growing up of Cu crystalline grain, and decreased the dispersion of Cu on the surface, which resulted in the poor activity of the catalyst for WGSR.
基金Project supported by the Introduction of Talent and Technology Cooperation Plan of Tianjin
文摘Pd@Zr/Ce O2 core-shell catalyst prepared by hydrothermal method was applied in CO oxidation reaction, exhibiting high CO oxidation activity at low temperature.XRD（X-ray diffraction） analysis demonstrated that the remarkable enhancement of catalytic performance was found to depend on the presence of more oxygen vacancies in the core-shell structure, which contributed higher content of and ready release of active oxygen species at low temperature, confirmed by H2-TPR（temperature programed reduction） results.Interestingly, introducing a small amount of zirconium（0.5 wt.%） exhibited a significant improvement of catalytic activity because the introduction of Zr further improved the amount of crystal defects and promoted the migration of oxygen species.
文摘The main results of hydrocracking of goudron under reduced pressure in the presence of a suspended catalyst have been analyzed. It was investigated the influence of pressure to hydrocracking process of goudron. It was determined that with increasing from 0.5 to 4.0 MPa, the yield of light oil products increased from 47% to 58% mass.
基金the National Natural Science Foundation of China(Project Nos.:51876061,51821004).
文摘Methanol steam reforming manifests great potential for generating hydrogen owing to its lower reaction temper-ature(200-300°C)and higher hydrogen/carbon ratio comparing with ethanol and methane reforming.In this case,methanol steam reforming is applied in various renewable energy systems to assist the energy conversion and improve the system efficiency.The performance of methanol steam reforming reaction strongly depends on the catalysts and reactor structure.In this paper,the development of the copper-based,the noble metal-based and the nanomaterial catalysts were summarized by analyzing the effects of different modification methods,which indicates that cutting the cost and simplifying the manufacturing process are the future goal of catalyst modifi-cation.Moreover,the reaction mechanism of different catalyst types was discussed.For the reactor performance,conventional,miniature,micro,and membrane reactors were discussed and compared,where conventional reac-tor with high CO tolerance is more suitable for industrial application while membrane reactor with high H 2 purity and compact structure is ideal for fuel cell technology.The integration of the methanol steam reforming system into renewable power systems was reviewed as well.Methanol steam reforming technology is of great potential in exhaust heat recovery,cogeneration system and other renewable energy field,where more comprehensive researches should be performed.
