摩砕酸化亜鉛粉末のESRスペクトルとH_2O_2分解反応に対する活性化エネルギ

概要

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The effects of dry grinding on the electron spin resonance spectra and catalytic activity of zinc oxide powder have been studied. The grinding was carried out in a vibration mill or in a ball mill, and the particle size and lattice strains of the products were determined from the X-ray diffraction pattern by applying the Stokes collected Fourier analysis. The catalytic activity was obtained by measuring the activation energy for the catalytic decomposition of hydrogen peroxide. The results obtained are as follows : (1) The activation energy decreased when the powder showed an increase of the sharp C peak and A peak in the ESR spectra, but it increased with increasing B peak. This suggests that the sharp C peak and the A peak originate from the donor center, while the B peak from the acceptor. (2) The broad C peak disappeared and a new peak appeared when tetracyanoethylene vapour was introduced. Thus, the broad C peak seems to represent the surface broken bonds. (3) The sharp C peak increased with decreasing the volume of ZnO crystallites. This fact shows that the sharp C peak would originate from the compressional strain (4) The A peak increased when ZnO crystallites were deformed, but it decreased by heating without accompanying weight change. These facts show that the A peak would originate from edge dislocations caused by shear stress.
社団法人日本材料学会の論文
1980-02-15