低碳化学与化工2024，Vol.49Issue(10)：72-80,9.DOI:10.12434/j.issn.2097-2547.20230411
助剂Pr6O11掺杂对CeO2-ZrO2-Al2O3材料及其负载单Pd三效催化剂性能的影响研究
Study on effects of surface modification by Pr6O11 as promoter on performances of CeO2-ZrO2-Al2O3 material and its supported Pd-only three-way catalyst
摘要
Abstract
Surface modification by promoters is one of the classic methods to improve the thermal stability,reducibility,and low-temperature activity of cerium-based materials and their supported Pd-only three-way catalysts.Revealing the mechanism of surface modification by promoters is of practical significance for the development of high-performance CeO2-ZrO2-Al2O3(CZA)materials to meet the increasingly strict regulations on gasoline vehicle exhaust emission and to solve the exhaust pollution.On the basis of the promoting effects of Pr6O11 on improving the low-temperature reducibility of CZA materials,the effects of different content of Pr6O11(0,3％,5％,7％,and 9％,mass fraction)on the redox performance and thermal stability of CZA materials were further studied.The characterization results of N2 adsorption/desorption,X-ray diffraction(XRD),H2 temperature programmed reduction(H2-TPR)and oxygen storage capacity show that the surface modification of CZA by Pr6O11 can reduce the driving force of CeO2-ZrO2(CZ)sintering and thus inhibit the growth of nanoparticles.At the same time,the introduction of Pr6O11 also promotes to produce more oxygen vacancies in the material,thus improving its reducibility and oxygen storage performance.Among them,when the content of Pr6O11 is 5％,the modified CZA exhibits the best thermal stability,redox performance and oxygen storage performance.After aging at 1000 ℃ for 4 h,it exhibits the highest specific surface area(85 m2/g)and pore volume(0.33 mL/g),the smallest crystal size of CZ(6.9 nm),the lowest reduction temperature(532 ℃)and the highest oxygen storage capacity of 109 μmol/gat 400 ℃.Therefore,the modified CZA supported Pd-only three-way catalyst exhibits the optimal catalytic activity,with the t50(required temperature at the pollutant conversion rate of 50％)of CO,NO,C3H8 and C3H6 reduced by 6 ℃,15 ℃,18 ℃ and 6 ℃,respectively,compared to the unmodified catalysts.In summary,the low-temperature activity of Pd-only thee-way catalysts can be improved by adding an appropriate amount of Pr6O11 to the CZA support,which is simple,economical,and has great application prospects.关键词
尾气净化/表面改性/CeO2-ZrO2-Al2O3/Pr6O11Key words
exhaust purification/surface modification/CeO2-ZrO2-Al2O3/Pr6O11分类
化学化工引用本文复制引用
张俊杰,王大军,李珊珊,李洁,陈耀壮,韩太宇,杨稹祯,王光永..助剂Pr6O11掺杂对CeO2-ZrO2-Al2O3材料及其负载单Pd三效催化剂性能的影响研究[J].低碳化学与化工,2024,49(10):72-80,9.基金项目
四川省自然科学基金-青年科学基金(2022NSFSC1206). （2022NSFSC1206）
