SCR脱硝中催化剂表面NH_4HSO_4生成及分解的原位红外研究  

FT-IR study of formation and decomposition of ammonium bisulfates on surface of SCR catalyst for nitrogen removal

作　　者：束航 张玉华[1] 范红梅[1] 张亚平[1] 杨林军[1] 

机构地区：[1]东南大学能源与环境学院能源热转换及其过程测控教育部重点实验室,江苏南京210096

出　　处：《化工学报》2015年第11期4460-4468,共9页CIESC Journal

基　　金：国家重点基础研究发展计划项目(2013CB228505)~~

摘　　要：采用工业用V2O5-WO3/Ti O2催化剂,基于傅里叶原位红外光谱(in situ FT-IR)技术考察了SCR脱硝过程中催化剂表面NH4HSO4的生成与分解特性。结果表明:在V2O5-WO3/Ti O2催化剂表面ABS的生成可由催化剂V═O基团上Lewis酸上配位吸附活化态的NH3在O2环境中与SO2反应生成,也可由SO2与催化剂表面反应生成的吸附态金属硫酸盐中间物VOSO4与气态NH3直接反应生成;NO能通过与NH4HSO4中的NH+4直接反应来降低NH4HSO4降解的温度窗口,促进其在催化剂表面的分解行为,NO的脱除与NH4HSO4的生成是相互抑制关系;NH4HSO4本身的负载量影响其分解与挥发行为。The mechanism of ammonium bisulfate formation and decomposition over a commercial V2O5-WO3/TiO2catalyst was explored using FT-IR. The results suggest that the formation of ammonium bisulfates mainly occurs in two ways： reaction between activated NH3 adsorbed coordinatedly on Lewis acid sites of catalyst V═O groups and SO2 under atmosphere containing O2;and reaction between absorbed intermediate of metal sulfates VOSO4 and gaseous NH3. NO could react directly with NH＋4 in NH4HSO4, which could lower its decomposition temperature, promoting the catalytic decomposition of adsorbed bisulfates （ABS） on catalyst surface. So, there is mutual inhibition between NO removal and ABS formation. Loading of ABS deposited on catalyst surface also affects its decomposition and volatilization.

关 键 词：原位红外光谱 选择催化还原 催化剂 脱硝 NH4HSO4 化学反应 

分 类 号：X511[环境科学与工程—环境工程]