Recent Survey of Catalysis by Solid Metal Sulfates
作者:
T. Takeshita,
R. Ohnishi,
K. Tanabe,
期刊:
Catalysis Reviews
(Taylor Available online 1974)
卷期:
Volume 8,
issue 1
页码: 29-63
ISSN:0161-4940
年代: 1974
DOI:10.1080/01614947408071856
出版商: Taylor & Francis Group
数据来源: Taylor
摘要:
The relationships between the surface properties of ionic salts, in particular metal sulfates, and their catalytic activities have intrigued us for some time [l]. They offer a useful model for linking homogeneous to heterogeneous catalysis. A metal sulfate, for example NiSO4·7H2O, develops a significant degree of acidity-and hence catalytic activity-only after heating causes deaquation. In 1965, on the basis of the physical and chemical characterization of changes accompanying such a process, the mechanism of surface activation was rationalized in terms of an intermediate, mestastable phase formed during the transition from one crystal modification to another [29]. During this change the nickel system exhibits a maximum acidity at an acid strength corresponding to that of 50% H2SO4about half way between the monohydrate and anhydrous form. These acidic sites, attributed to vacant coordination sites on the above intermmediate crystal lattice, are responsible for the catalytic activity of solid metal sulfates.
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