【摘要】 为开发高效、成本低廉的碳酸二甲酯(DMC)合成工艺，以Naβ(25)、NaZSM-5(25)、NaY(6)、NaY(8)和NaY(10)分子筛为载体，采用浸渍法制备了负载型Pd催化剂，并将其首次用于草酸二甲酯(DMO)脱羰基反应。采用X射线衍射、X射线光电子能谱、透射电镜和傅里叶变换红外光谱等表征方法对催化剂的组成、价态、孔结构、形貌以及晶型进行分析，并对其催化性能进行评价。结果表明，使用Pd/NaY(6)催化剂催化DMO脱羰基合成DMC,在反应温度220℃、反应时间90 min、催化剂用量1.0 g、1,4-二氧六环与DMO质量比4∶1、Pd负载量(w)0.2%的条件下，DMO转化率可达82.59%,DMC选择性可达62.33%。通过对催化剂稳定性的研究发现，经过5次循环再生后，催化剂对DMO脱羰基反应仍具有良好的催化活性。最后，合理推测出Pd/NaY(6)催化剂催化DMO脱羰基合成DMC的反应机理。更多还原

【Abstract】 In order to develop a high efficient and low cost synthetic process for dimethyl carbonate(DMC),supported Pd catalysts were prepared by impregnation method on Naβ(25),NaZSM-5(25),NaY(6),NaY(8),and NaY(10) zeolites, and it was first used in the decarbonylation reaction of dimethyl oxalate(DMO). The composition, valence, pore structure, morphology and crystal of the catalysts were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy and Fourier transform infrared spectroscopy. The results showed that DMC was synthesized by the decarbonylation of DMO over Pd/NaY(6) catalyst. Under the optimum conditions such as a reaction temperature of 220 ℃,a reaction time of 90 min, a catalyst dosage of 1.0 g, a mass ratio of 1,4-dioxane to DMO of 4∶1,and a Pd loading of 0.2%,the conversion of DMO and the selectivity of DMC were 82.59% and 62.33%,respectively. After five cycles of regeneration, the catalyst showed good catalytic activity for DMO decarboxylation. Finally, the reaction mechanism of DMC synthesis by DMO decarbonylation over Pd/NaY(6) catalyst was reasonably deduced.更多还原