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用SSA、PSD、XRD及SEM等实验手段研究了自制Raney-Cu催化剂在不同温度及不同气氛中的烧结行为。发现催化剂表面的烧结分为前后两个不同阶段,各对应于表面上不同孔径的收缩及封堵,催化剂表面的烧结程度与各种气体分子的吸附强度相联系。建立了表面积收缩的动力学方程,对烧结机理进行了探讨。文章指出,烧结行为包括表面及体相两方面的变化。积炭的产生掩盖了铜催化剂表面积的收缩,但加速了体相结晶度的提高。应用量子力学方法计算的烧结起始温度与实验结果吻合较好。
The sintering behavior of self-made Raney-Cu catalysts at different temperatures and different atmospheres was investigated by means of SSA, PSD, XRD and SEM. It is found that the sintering of the catalyst surface is divided into two different stages before and after, each corresponding to the shrinkage and plugging of different pore sizes on the surface, and the degree of sintering on the catalyst surface is related to the adsorption strength of various gas molecules. The kinetic equation of surface area shrinkage was established and the sintering mechanism was discussed. The article points out that the sintering behavior includes both surface and bulk changes. The coke production masks the shrinkage of the copper catalyst surface area, but accelerates the increase of bulk crystallinity. The initial sintering temperature calculated by quantum mechanics method is in good agreement with the experimental results.