摘要
为提高商用SCR催化剂对Hg^0(零价汞)的催化氧化活性,研究了过渡金属对其进行掺杂改性的方法,并利用固定床反应平台考察了不同试验条件下改性催化剂对Hg^0的氧化效率.结果表明:Y、Zn、Ni和Zr等过渡金属的掺杂可明显抑制SCR催化剂的催化活性,而Fe、Cu掺杂改性SCR催化剂对Hg^0的催化氧化性能有显著提升.在反应温度为350℃、空速比为370 000 h^(-1)、φ(HCl)为1×10^(-5)的条件下,Fe、Cu掺杂改性的SCR催化剂对Hg^0的氧化效率均能达到90%以上,并且Fe掺杂改性后的SCR催化剂的脱硝性能也未受到明显影响.借助XRD和XPS等表征手段对反应前后Fe掺杂改性SCR催化剂进行了研究表明Fe改性SCR催化剂遵循Mars-Maessen和Langmuir-Hinshelwood机制,可明显提高对Hg^0的催化氧化效率,因此,应用前景较好.
In order to improve the catalytic oxidation activity of the commercial selective catalytic reduction（SCR） catalyst for removal of Hg^0 in flue gas,a transition metal oxides doped SCR catalyst by impregnation method was employed to improve the Hg^0 catalytic oxidation.Moreover,the fixed bed reaction platform was used to investigate the modified catalyst under different test conditions for Hg^0 catalytic oxidation efficiency.Hg^0 catalytic oxidation efficiencies of the modified catalysts by transition metals were tested in a pack-bed reactor system under different experimental conditions.The results showed that the catalytic performance of the SCR catalyst was remarkably inhibited by Y,Zn,Ni and Zr,and greatly enhanced by Fe and Cu.The Hg^0 oxidation efficiency of the SCR doped with Fe or Cu was over 90%when the reaction temperature,space velocity and HCl concentration were set as 350 ℃,370,000 h^（-1） and 1 × 10^（-5）,respectively.Furthermore,Fe doping the catalyst did not obviously affect the NO_x removal efficiency of the SCR catalyst.In addition,XRD and XPS were employed to characterize the SCR catalyst doped with Fe.The results indicated that the SCR catalyst doped with Fe showed good performance of Hg^0 oxidation according to the Mars-Maessen and Langmuir-Hinshelwood mechanisms.Therefore,SCR modified with Fe has good application prospects for the simultaneous removal of elemental mercury and NO_x.
出处
《环境科学研究》
EI
CAS
CSSCI
CSCD
北大核心
2016年第3期397-403,共7页
Research of Environmental Sciences
基金
国家自然科学基金项目(51278294)
关键词
燃煤烟气
催化氧化
SCR
零价汞
coal-fired flue gas
catalytic oxidation
SCR
elemental mercury
作者简介
马步宇（1993-），男，山西太原人，myluck@sjtu．edu．cn．
责任作者，瞿赞（1977-），男，湖南湘阴人，副教授，博士，主要从事环境化工与大气污染控制工程研究，quzan@sjtu．edu．cn
