利用同步辐射研究正庚烷火焰燃烧特性

利用同步辐射单光子电离和分子束取样技术并结合飞行时间质谱仪,在低压、预混、燃油当量比为1.0情况下研究正庚烷层流火焰的燃烧特性.共检测出24种中间产物,并计算出其摩尔分数.在燃烧反应前期,主要中间产物是酮、醚类物质.在燃烧反应后期,主要中间产物是碳氢化合物,燃烧反应前期的中间产物在燃烧反应后期继续氧化.乙烯在所有中间产物中摩尔分数最大的.另外,火焰中丙炔与苯有极大的相关性.     

同步辐射单光子电离技术研究乙醚富燃火焰

本文利用同步辐射单光子电离和分子束质谱技术研究了乙醚在富燃条件下的低压预混火焰.通过测量光电离质谱和扫描光电离效率谱,我们鉴别了该火焰中大部分的燃烧中间体及产物.此外,通过改变燃烧炉的位置测量光电离质谱,得到了各燃烧中间体及产物的摩尔分数曲线.实验结果为深入研究乙醚燃烧动力学并揭示含氧有机化合物在火焰中的反应机理提供了依据.     

苯高压氧化实验和模型研究

利用射流搅拌反应器研究了1.2 MPa、当量比为1、温度范围880～1010 K下苯的氧化反应动力学。利用气相色谱和色谱质谱联用仪检测到了20种产物和中间组分。根据实验结果发展了一个272种组分、1702个反应的动力学模型,合理地模拟了实验结果。与常压实验相比,检测到乙醛、丙烯醛、甲苯、苯乙烯、苯甲醛、萘、茚和二苯并呋喃等新组分;反应的初始温度由1000 K降低为950 K,反应区间由300 K减少至70 K;探明了高压低温下苯通过苯醌消耗的新分解路径。根据敏感性分析,A₁+OH=A₁-+H₂O是促进其消耗最重要的反应,A₁OH+O₂=A₁O+HO₂是抑制苯消耗最重要的反应。本模型合理预测了苯在常压的氧化和不同压力下的层流火焰速度。     

利用同步辐射研究汽油及其混合物的火焰成分特征

本文利用同步辐射和分子束取样技术并结合飞行时间质谱仪,分别检测了加入MTBE前后的汽油在氧气中的燃烧产物.通过比较标准汽油与MTBE/汽油在火焰中的成分差异,以及几种典型燃烧产物的空间分布曲线,分析了MTBE对汽油的微观影响机理,为建立燃烧反应动力学模型提供了参考.     

利用原位傅里叶变换红外光谱诊断催化剂的特性和催化活性

The present work establishes a systematic approach based on the application of in-situ Fourier transform infrared spectroscopy (FTIR) for the investigation of the crystal structure, thermal stability, redox behavior (temperature-programmed reduction/temperatureprogrammed re-oxidation) as well as the catalytic properties of Co₃O₄ thin films. The syntheses of Co₃O₄ were achieved by chemical vapor deposition in the temperature range of 400-500℃. The structure analysis of the as-prepared material revealed the presence of two prominent IR bands peaking at 544 cm^-1 (υ₁) and 650 cm^-1 (υ₂) respectively, which originate from the stretching vibrations of the Co-O bond, characteristic of the Co₃O₄ spinel. The lattice stability limit of Co₃O₄ was estimated to be above 650℃. The redox properties of the spinel structure were determined by integrating the area under the emission bands υ₁ and υ₂ as a function of the temperature. Moreover, Co₃O₄ has been successfully tested as a catalyst towards complete oxidation of dimethyl ether below 340 ℃. The exhaust gas analysis during the catalytic process by in situ absorption FTIR revealed that only CO₂ and H₂O were detected as the final products in the catalytic reaction. The redox behavior suggests that the oxidation of dimethyl ether over Co₃O₄ follows a Mars-van Krevelen type mechanism. The comprehensive application of in situ FTIR provides a novel diagnostic tool in characterization and performance test of catalysts.