摘要
以Pt/SBA-15为催化剂,考察催化剂载体中添加Sm对于苯的完全氧化反应活性和热稳定性影响。采用了一种简便的记录起燃温度曲线和催化剂热稳定性评价方法,即向装载好催化剂的固定床反应器中持续通入恒定流量的反应气,逐步阶段性升高反应温度,同时在线检测出口尾气的浓度变化,得到起燃温度曲线后,继续提高反应温度,然后恒定在某一设定的温度(如550℃)持续运行较长时间,期间定时在线取样分析,如果有必要还可以连续考察降温情况下催化剂的反应活性情况。研究结果表明,几种催化剂低温活性次序为:Pt/SBA-15≈Pt/4%Sm2O3/SBA-15>Pt/Sm2O3>4%Sm2O3/SBA-15,而对于高温稳定性则是Pt/4%Sm2O3/SBA-15>Pt/1.2%Sm2O3/SBA-15>Pt/SBA-15,Pt/Sm-SBA-15(SG)>Pt/SBA-15(SG)。总之,Sm的添加虽然未能提高Pt/SBA-15的低温催化活性,但是能明显提高催化剂在高温情况下活性的稳定性。1%Pt/4%Sm2O3/SBA-15同时具备较好的低温催化活性和高温稳定性,具有较好的应用前景。
The Sm addition effects on the reactivity and thermal stability of Pt/SBA-15 for catalytic complete oxidation of benzene were investigated.A simple method for recording the burning-off curves and the evaluation for the thermal stability of catalysts was adopted,that is,a constant flow of reaction gas was continuously introduced into a fixed bed reactor loaded with catalyst.The reaction temperature was increased step by step,and the on-line outlet concentrations of benzene were detected after time interval sampling.The burning-off curves could be recorded during this stage.After that,the reaction temperature was increased continuously,and kept at a certain value(e.g.550℃),the on-line sampling analysis was kept at a set time.If necessary,the reaction temperature could be decreased step by step to check the activity variation of the catalyst.The results indicated that the activity order for four catalysts at lower temperature stage was Pt/SBA-15≈Pt/4%Sm2O3/SBA-15>Pt/Sm2O3>4%Sm2O3/SBA-15,while the stability order at high temperature was Pt/4%Sm2O3/SBA-15>Pt/1.2%Sm2O3/SBA-15>Pt/SBA-15,Pt/Sm-SBA-15(SG)>Pt/SBA-15(SG).In conclusion,Sm can not improve the catalytic activity of Pt/SBA-15 at low temperature,but can significantly improve the stability of the catalyst at high temperature.At the same time,1%Pt/4%Sm2O3/SBA-15 has good catalytic activity at low temperature and high temperature stability,and has a good application prospect.
作者
毛建新
袁子卿
严红绡
周仁贤
MAO Jianxin;YUAN Ziqing;YANG Hongxiao;ZHOU Renxian(Institute of Catalysis,Chemistry Department,Zhejiang University,Hangzhou 310007,Zhejiang,China)
出处
《化工学报》
EI
CAS
CSCD
北大核心
2020年第1期306-313,共8页
CIESC Journal
基金
国家重点研发计划项目(2016YFC0204300)
