关键词: 阳离子, 溶液离子交换, CuY, 氧化羰基化, 甲醇, 催化

CeY, LaY and CsY zeolites were firstly prepared by ion-exchange of NaY zeolite with aqueous solution of cerous nitrate, lanthanum nitrate and cesium nitrate. Then CuCeY, CuLaY and CuCsY catalysts were prepared by secondary ion-exchange of CeY, LaY and CsY zeolites with ammonia solution of copper nitrate (pH＝9.5), and activated by calcinating at the temperature of 600 ℃. Compared with CuY catalyst, all of the prepared CuCeY, CuLaY and CuCsY catalysts exhibited higher catalytic activity in the oxidative carbonylation of methanol to dimethyl carbonate. Based on the characterization of the microstructure of catalysts by XRD, H₂-TPR, CO-TPD, CH₃OH-TPD, XPS and elementary analysis, it was shown that cerium and lanthanum cations promoted Cu^2＋ to locate in the supercage of zeolite, and more Cu^2＋ auto-reduced to Cu^＋ in the process of calcinating activation in inert atmosphere, which was conducive to the improvement of catalytic activity. Cesium cation blocked Cu^2＋ locating in the supercage of zeolite, which was not likely to the improvement of catalytic activity. However, the introduction of the Ce, La or Cs cations resulted in CO weakening adsorption and CH₃OH intensifying adsorption other than CuCeY. CuCsY catalyst exhibited highest catalytic activity for it adsorped CO the weakest and adsorped CH₃OH the strongest. Besides, the introduction of the cations were all not conducive to auto-reduction progress of Cu^2＋ to Cu^＋, but compared with CuCeY and CuLaY catalysts, CuCsY had a easier auto-reduction progress of Cu^2＋ to Cu^＋, which was likely to the improvement of catalytic activity.

Key words: cation, solution ion-exchange, CuY, oxycarbonylation, methanol, catalysis