摘要
采用前驱体转化法将四氧化三锰分别与硝酸、硫酸、醋酸进行歧化反应,制备了3组γ-二氧化锰催化剂(Mn-N、Mn-S、Mn-A),研究了不同酸对产物结构和形貌的影响。通过X射线衍射(XRD)、扫描电镜(FE-SEM)、透射电镜(HR-TEM)、氮气吸附-脱附、X射线光电子能谱(XPS)、氢气程序升温还原(H_(2)-TPR)和氧气程序升温脱附(O_(2)-TPD)等表征方法系统分析了各产物的物化性质,并采用甲苯催化燃烧作为探针反应用于评估γ-二氧化锰催化剂的活性。结果表明,经硝酸处理得到的催化剂Mn-N具有最佳的甲苯催化燃烧活性,在质量空速为40000 mL/(g·h)条件下,起燃温度T_(10)(对应转化率为10%)为190℃,完全燃烧温度T_(90)(对应转化率为90%)为229℃。这可能与其具有较大比表面积、较高的锰(Ⅲ)和吸附氧物种含量、较好的可还原性和晶格氧流动能力有关。此外,经过连续30 h的稳定性实验,Mn-N仍可保持良好的催化活性。
Three groups ofγ-MnO_(2)catalysts(Mn-N,Mn-S,Mn-A)were prepared by disproportionation reaction between Mn_(3)O_(4) and nitric acid,sulfuric acid,and acetic acid,respectively.The effect of different acid on the structure and morphology of the products was studied.The physical and chemical properties of the products were systematically analyzed by X-ray diffraction(XRD),scanning electron microscopy(FE-SEM),transmission electron microscopy(HR-TEM),nitrogen adsorption desorption,X-ray photoelectron spectroscopy(XPS),hydrogen temperature programmed reduction(H_(2)-TPR)and oxygen temperature programmed desorption(O_(2)-TPD).And toluene catalytic combustion was used as a probe reaction to evaluate the activity ofγ-MnO_(2)catalyst.The results showed that the catalyst Mn-N treated with nitric acid had the best cata⁃lytic combustion activity for toluene.Under the condition of mass space velocity of 40000 mL/(g·h),the ignition temperature T_(10)(corresponding conversion of 10%)was 190℃,and the complete combustion temperature T_(90)(corresponding conversion of 90%)was 229℃.This may be related to its large specific surface area,high content of Mn(Ⅲ)and adsorbed oxygen species,good reducibility and lattice oxygen flow ability.In addition,Mn-N could still maintain good catalytic activity after continuous stability experiments for 30 h.
作者
唐诗昌
程高
刘琪
叶凡
孙明
余林
TANG Shichang;CHENG Gao;LIU Qi;YE Fan;SUN Ming;YU Lin(Key Laboratory of Clean Chemistry Technology of Guangdong Regular Higher Education,School of Chemical Engineering and Light Industry,Guangdong University of Technology,Guangzhou 510006,China)
出处
《无机盐工业》
CAS
CSCD
北大核心
2022年第6期134-141,共8页
Inorganic Chemicals Industry
基金
国家自然科学基金项目(21576054)
广东省科技创新战略专项项目(2018A030310563)
广东省自然科学基金项目(2019B1515120087)
广东省普通高校基础研究与应用基础研究重点项目(2018KZDXM031)。
