在异相催化反应过程中,扩散与传热等物理传递过程的阻力,既影响反应的转化率,又影响选择性。工业上这样的例子很多。例如,在 Fe 催化剂上的合成氨反应;在 Pt 或 V_2O_5催化剂上 SO_2氧化反应;萘氧化制苯酐等等。为了降低催化剂内部扩散与传热等传递阻力的影响,可以采取减小颗粒度的办法。例如,采用微球催化剂的沸腾床。但是,对于固定床而 In the process of heterogeneous catalysis, the resistance of the process of physical transfer such as diffusion and heat transfer not only affects the reaction conversion rate but also affects the selectivity. There are many examples in industry. For example, ammonia synthesis on Fe catalyst; oxidation of SO 2 on Pt or V 2 O 5 catalyst; oxidation of naphthalene to phthalic anhydride and so on. In order to reduce the catalyst diffusion and heat transfer resistance such as the impact can be taken to reduce the granularity approach. For example, a bubbling bed using a microsphere catalyst. However, for fixed bed