苯酚和草酸二甲酯在不同分子筛催化下的酯交换反应

Synthesis of Diphenyl Oxalate from the Transesterification of Dimethyl Oxalate with Phenol over the Different Molecular Sieve Catalysts

研究了以TS 1、H ZSM 5、Hβ和H 丝光沸石等不同分子筛为催化剂 ,苯酚和草酸二甲酯酯交换合成草酸二苯酯反应。通过对催化剂进行吸附吡啶的红外光谱和NH3 TPD表征 ,考察了不同分子筛催化剂的酸性和酸强度对草酸二苯酯合成反应的影响 ,确定了催化剂上的弱酸中心是催化苯酚和草酸二甲酯酯交换合成草酸二苯酯反应的活性位 ,且催化剂的酸性中心越多 ,酸量越大 ,催化活性越好。

Diphenyl oxalate was prepared by the transesterification of dimethyl oxalate with phenol over the different molecular sieve catalysts. The main product diphenyl oxalate and the intermediate methyl phenyl oxalate were qualitatively analyzed by GC/MS. The activities of catalysts for the transesterification of dimethyl oxalate with phenol were evaluated. The characterization of catalysts was carried out using FTIR of absorbed pyridine and NH 3-TPD. The result showed that weak acid sites were the active sites for the transesterification of dimethyl oxalate with phenol. The more the amount of weak acid sites on the catalyst was, the higher activity the catalyst had. The strong acid sites had a significant influence on the production of byproduct anisole.