摘要
本文用穆斯堡尔谱法对郑州大学开发的球形氨合成催化剂A_(6)C型和HAC型进行了研究。结果是不同工艺制成的氨合成熔铁催化剂基本相组成接近,但维氏体含量及助剂分布的均匀程度有较大的差异。球形A_(6)C催化剂较之配方接近的无定形A_(6)催化剂含有较多的维氏体,且Al+3进入晶格较多;A_(6)C与HAC两种球形催化剂,由于助剂含量不同,维氏体量与助剂分布状况的不同,引起催化剂还原性、活性及耐热性的差别。据此对球形催化剂的铁比(Fe_(+2)/Fe_(+3))控制及使用条件提出一些看法。
The mossbauer spectra of catalysts A_(6)C(spherical), HAC (spherical low-temperature catalyst) and A_(6) (irregular), and promoterless samples were measured by the mossbauer spectrometer AME-50.The increasing of Wustite (Fe_(1-x)O) content and evenness of promoters distribution (more Al^(+3) has entered into Fe_(3)O_(4) lattice) of spherical catalysts may be derived from the particular technology of preparation by which a rapid cooling was carried out in water.There is higher Wustite content of catalyst HAC than that of A_(6)C for the same iron ratio. It may be derived mainly from the different amounts of Al_(2)O_(3) in the catalysts.More Wustite in catalyst results in easy reduction and high aetivi-ty, but less thermal stability. The even distribution of promoters counteracts the later weakness and ultimately the thermal stability rises in practice.The spherical catalysts ought to have their optimum iron ratios of Fe_(+2)/Fe_(+3). The catalyst HAC should be prepared with smaller iron ratio than A_(6)C, and the catalyst HAC can be used very well in a wide range of temperature.
作者
李利民
王文祥
Li Limin;Wang Wenxiang(Department of Chemistry,Zhengzhou University,Zhengzhou)
出处
《高等学校化学学报》
SCIE
EI
CAS
1983年第6期763-768,共6页
Chemical Journal of Chinese Universities
