本文利用XRD、TEM、催化剂电导测定及活性评价等实验手段,研究了电导和Cr_2O_3晶粒度对Cr_2O_3/Al_2O_3催化剂催化性能的影响。结果表明,在反应条件下催化剂为n型半导体,其催化活性与Cr_2O_3晶粒大小和催化剂的电导大小密切相关,最大活性对应的具有适宜Cr_2O_3晶粒度的催化剂,其电导值呈现最大,Cr~(3+)和Cr~(2+)均可成为甲苯脱甲基的活性中心,而Cr~(2+)更为有利。 In this paper, the effects of conductance and grain size of Cr 2 O 3 on the catalytic performance of Cr 2 O 3 / Al 2 O 3 catalysts were investigated by means of XRD, TEM, catalytic conductivity determination and activity evaluation. The results show that the catalyst is n-type semiconductor under the reaction conditions, the catalytic activity is closely related to the grain size of Cr 2 O 3 and the conductivity of the catalyst, and the maximum activity corresponds to the catalyst with appropriate grain size of Cr 2 O 3, Both Cr3 + and Cr2 + could be the demethylation centers of toluene, while Cr2 + was more favorable.