【摘要】 采用浸渍法制备了一系列不同钒和钨负载量的V2O5-WO3/TiO2催化剂样品,对样品NH3选择性催化还原NO性能进行了评价,并用BET、XRD、XPS等手段对催化剂样品的表面形态进行了表征.研究发现,钒的负载量对催化剂的比表面积和催化活性有显著影响,当钒负载量从1%升高到8%时,催化剂比表面积下降了16 m2/g,最高活性温度降低了约100℃.钨起到稳定剂和助剂的双重作用,当钒负载量为1%时,钨负载量从0升高到6%,催化剂比表面积仅下降了3 m2/g,而活性温度窗口向高温和低温各拓宽了约50℃.研究表明钒和钨负载量都能影响催化剂表面的VOx物种,但对催化剂的表面晶型没有明显影响.更多还原

【Abstract】 V₂O₅-WO₃/TiO₂ catalysts with different vanadium and tungsten loadings were prepared by impregnation method.The activities of selective catalytic reduction（SCR） of NO with NH₃ were measured and surface characteristics of those samples were characterized.It is found that both the surface areas and catalytic activities are influenced by vanadium loadings.When the vanadium loadings increased from 1% to 8%,the catalyst surface areas decreased by 16（m²/g）,while the highest activity temperature was reduced by about 100℃.Tungsten acts as stabilizer and promoter of the SCR catalyst.When the vanadium loading was 1%,an increase of tungsten loadings from 0 to 6% resulted in the decrease of the catalyst surface areas by only（3 m²/g）,while the activity window was expanded to both high and low temperature range each by about 50℃.Vanadium and tungsten loadings have an effect on the surface VO_x,but do not change the surface crystal structure of the catalysts.更多还原