The alkali-metal Na adsorption on Si(100)2×1 surface and its promoted oxidation and Si oxide growth have been investigated by means of thermal desorption,work function,Auger electron spectroscopy and photoemissio...The alkali-metal Na adsorption on Si(100)2×1 surface and its promoted oxidation and Si oxide growth have been investigated by means of thermal desorption,work function,Auger electron spectroscopy and photoemission electron spectroscopy.The experimental data showed that there was a new state,interface electron state,near the Fermi level after the deposition of Na atoms.It was found that the presence of Na always caused an increase of the oxygen initial uptake whereas the promotion of Si oxide growth was observed only at the coverage of Na greater than 0.5 ML.A new mechanism of Na-promoted Si oxide growth is suggested in this paper.展开更多
This work reports the enhancing effect of a highly cost effective and efficient metal, Fe, incorporation to Co or Ni based Mo/Al2O3 catalysts in the oxidative desulfurization （ODS） of dibenzothiophene （DBT） using ...This work reports the enhancing effect of a highly cost effective and efficient metal, Fe, incorporation to Co or Ni based Mo/Al2O3 catalysts in the oxidative desulfurization （ODS） of dibenzothiophene （DBT） using H2O2 and formic acid as oxidants. The influence of operating parameters i.e. reaction time, catalyst dose, reaction temperature and oxidant amount on oxidation process was investigated. Results revealed that 99% DBT conversion was achieved at 60℃ and 150 min reaction time over Fe-Ni-Mo/Al2O3. Fe tremendously enhanced the ODS activity of Co or Ni based Mo/Al2O3 catalysts following the activity order：Fe-Ni-Mo/Al2O3 〉 Fe-Co-Mo/Al2O3 〉 Ni-Mo/Al2O3 〉 Co-Mo/Al2O3, while H2O2 exhibited higher oxidation activity than formic acid over all catalyst systems. Insight about the surface morphology and textural properties of fresh and spent catalysts were achieved using scanning electron microscopy （SEM）, X-ray diffraction （XRD）, energy dispersive X-ray （EDX） analysis, Atomic Absorption Spectroscopy （AAS） and BET surface area analysis, which helped in the interpretation of experimental data. The present study can be deemed as an effective approach on industrial level for ODS of fuel oils crediting to its high efficiency, low process/catalyst cost, safety and mild operating condition.展开更多
文摘The alkali-metal Na adsorption on Si(100)2×1 surface and its promoted oxidation and Si oxide growth have been investigated by means of thermal desorption,work function,Auger electron spectroscopy and photoemission electron spectroscopy.The experimental data showed that there was a new state,interface electron state,near the Fermi level after the deposition of Na atoms.It was found that the presence of Na always caused an increase of the oxygen initial uptake whereas the promotion of Si oxide growth was observed only at the coverage of Na greater than 0.5 ML.A new mechanism of Na-promoted Si oxide growth is suggested in this paper.
文摘This work reports the enhancing effect of a highly cost effective and efficient metal, Fe, incorporation to Co or Ni based Mo/Al2O3 catalysts in the oxidative desulfurization （ODS） of dibenzothiophene （DBT） using H2O2 and formic acid as oxidants. The influence of operating parameters i.e. reaction time, catalyst dose, reaction temperature and oxidant amount on oxidation process was investigated. Results revealed that 99% DBT conversion was achieved at 60℃ and 150 min reaction time over Fe-Ni-Mo/Al2O3. Fe tremendously enhanced the ODS activity of Co or Ni based Mo/Al2O3 catalysts following the activity order：Fe-Ni-Mo/Al2O3 〉 Fe-Co-Mo/Al2O3 〉 Ni-Mo/Al2O3 〉 Co-Mo/Al2O3, while H2O2 exhibited higher oxidation activity than formic acid over all catalyst systems. Insight about the surface morphology and textural properties of fresh and spent catalysts were achieved using scanning electron microscopy （SEM）, X-ray diffraction （XRD）, energy dispersive X-ray （EDX） analysis, Atomic Absorption Spectroscopy （AAS） and BET surface area analysis, which helped in the interpretation of experimental data. The present study can be deemed as an effective approach on industrial level for ODS of fuel oils crediting to its high efficiency, low process/catalyst cost, safety and mild operating condition.
