焙烧温度对纳米钒催化剂性能的影响研究

采用不同的焙烧温度制备纳米钒催化剂,并进行微观形貌、活性、机械强度和耐腐蚀性能的测试与分析。结果表明,650℃焙烧纳米钒催化剂具有最佳的活性、机械强度和耐腐蚀性能;在试样活性测试过程的耐热温度为500℃时,650℃焙烧的试样的的活性较500℃焙烧的试样增加24.6%、较800℃焙烧的试样增加38.6%;机械强度较500℃焙烧的试样提高28.4%、较800℃焙烧的试样提高45.8%;腐蚀电位较500℃焙烧的试样正移97 m V、较800℃焙烧的试样正移222 m V。

Hydrothermal Synthesis and Efficient Visible Light Photocatalytic Properties of InVO4 Hierarchical Microspheres and InVO4 Nanowires

In this work, InVO4 hierarchical microspheres and InVO4 nanowires were successfully synthesized by a facile hydrothermal method. Field emission scanning electron microscopy showed that InVO4 crystals can be fabricated in different morphologies by simply manipulating the reuction parameters of hydrothermal process. The as-prepared InVO4 photocatalysts exhibited higher photocatalytic activities in the degradation of rhodamine B under visible-light irradiation （λ〉420 nm） compared with commercial P25 TiO2. Furthermore, the as-synthesized InVO4 hierarchical microspheres showed higher photocatalytic activity than that of InVO4 nanowires. Up to 100% Rh B （3 μmol/L） was decolorized after visible-light irradiation for 40 min. In addition, the reason for the difference in the photocatalytic activities for InVO4 hierarchical microspheres and InVO4 nanowires was studied based on their structures and morphologies.

Application of sodium titanate nanotubes doped with vanadium(VNaTNT) as a heterogeneous catalyst for oxidation of sulfides at room temperature

A heterogeneous titanate nanotube （TNT） catalyst containing TiO2, Na, and V has been synthesized and used in the chemoselective oxidation of sulfides to the corresponding sulfoxides in the presence of 30%H2O2 in water. Some of the advantages of our method include excellent yields, heterogene‐ous conditions, simplicity, compatibility with a variety of functionalities, and ease of isolation of the products. Fourier transform infrared spectroscopy, X‐ray diffraction, scanning electron microscopy, transmission electron microscopy, and N2 adsorption were used for structural and textural charac‐terization of the catalyst （VNaTNT）.

Carbon nanotubes loaded with vanadium oxide for reduction NO with NH_3 at low temperature

The catalytic activity of carbon nanotubes-supported vanadium oxide(V_2O_5/CNTs) catalysts in the selective catalytic reduction(SCR) of NO with NH_3 at low temperatures(<250℃) was investigated.The effects of V_2O_5loading,reaction temperature,and presence of SO_2 on the SCR activity were evaluated.The results show that V_2O_5/CNTs catalysts exhibit high activity for NO reduction with NH_3 at low-temperatures.The catalysts also show very high stability in the presence of SO_2.More interestingly,their activities are significantly promoted instead of being poisoned by SO_2.The promoting effect of SO_2 is distinctly associated with V_2O_5 loading,particularly maximized at low V_2O_5 loading,which indicated the role of CNTs support in this effect.The promoting effect of SO_2 at low temperatures suggests that V_2O_5/CNTs catalysts are promising catalytic materials for low-temperature SCR reactions.