以纳米二氧化锆为载体的Pd催化剂制备及还原缩合性能研究

Preparation of Nanosized Zirconium Dioxide Supported Palladium Catalyst and Research of Its Reduction and Condensation Performance

考察了不同制备方法得到的纳米二氧化锆为载体担载Pd催化剂对丙酮还原缩合的影响。纳米二氧化锆的制备方法对二氧化锆的物理性质和催化性能有较大的影响。不同的沉淀方法、陈化环境制备的纳米ZrO2,对不同的产物有不同的选择性,其中,在母液中373K陈化的二氧化锆为载体的催化剂对二异丁基酮(DIBK)的选择性较高,为61 43%;沉淀剂滴加到盐溶液中得到的二氧化锆为载体的催化剂对甲基异丁基酮(MIBK)的选择性较高,为63 70%。催化剂的酸性和Pd分散度表征结果表明,较高的Pd分散度、合适的酸性有利于MIBK的生成,较高的Pd分散度、较强的酸性有利于DIBK的生成。

The influence of preparation methods of nanosized ZrO_2-based supported palladium catalysts for synthesis of methyl isobutyl ketone(MIBK)/diisobutyl ketone(DIBK) from acetone in one step was investigated.The results indicate that the physical properties and the catalytic performance of the nanosized ZrO_2 are strongly influenced by the preparation methods.By heating Zr(OH)_4 in the mother liquor at 373 K for 3 h,the catalyst is more selective to DIBK,the selectivity for DIBK being 61.43%;with ZrO_2 prepared by dropwise addition of ammonium hydroxide to a solution of zirconyl chloride,the catalyst is more selective to MIBK,the selectivity for MIBK being 63.70%.The acid properties of the ZrO_2-based catalysts were characterized and the results indicate that high dispersion of palladium and moderate acidity of the catalyst is beneficial to the preparation of MIBK,while high dispersion of palladium and strong acidity of the catalyst is beneficial to the formation of DIBK.