Abstract:

A series of the zirconium (Zr)-modified Cu/SiO₂ catalysts were synthesized by ammonia-evaporation method and applied in the gas-phase hydrogenation of methyl 3-hydroxypropionate (3-HMP) to 1,3-propanediol (1,3-PDO). N₂ adsorption-desorption, XRD, ICP-OES, H₂-TPR, NH₃-TPD, CO₂-TPD, FTIR, TG-DTG, HRTEM, XPS and AES techniques were used for detailed characterizations. Introduction of the Zr species results in a strong interactions between the Cu and Zr species, leading to the generation of more copper phyllosilicate, and thus increasing the specific surface area of the catalyst as well as reducing the particle sizes of the copper species. The addition of Zr also made the copper species better be dispersed over the SiO₂ support, increased the Cu⁺ content and enhanced the electronic absorption of the substrate 3-HMP by the acyl and methoxide groups. Compared with the unmodified Cu/SiO₂ catalyst, the Zr-added (0.5%) Cu/SiO₂ catalyst showed better catalytic performance. The conversion of 3-HMP as 96.0% was achieved along with the 1,3-PDO selectivity of 84.3%, Resulting in a total yield of 80.9% for 1,3-PDO. These were the best results obtained currently at a high liquid hourly space velocity (LHSV) of 0.10h^-1.

Key words: methyl 3-hydroxypropionate, hydrogenation, 1,3-propanediol, Cu/SiO₂, Zr modification

摘要：

采用蒸氨法制备了锆（Zr）改性的Cu/SiO₂催化剂，用于3-羟基丙酸甲酯（3-HMP）气相加氢制1,3-丙二醇（1,3-PDO）。采用比表面积及孔分布测试、XRD、ICP-OES、H₂-TPR、NH₃-TPD、CO₂-TPD、FTIR、TG-DTG、HRTEM、XPS和AES等手段对催化剂进行了详细表征，发现Zr物种的加入使得Cu和Zr物种之间发生了强相互作用，产生了较多的层状硅酸铜，在结构方面提高了催化剂的比表面积，降低了铜物种的粒径，促进铜物种的分散，且在电子调控方面提高了Cu⁺的含量，增强了催化剂吸附酰基和甲氧基的能力。与未改性的Cu/SiO₂催化剂相比，在相同反应条件下，Zr掺杂量为0.5%的Cu/SiO₂催化剂表现出更高的催化性能，获得3-羟基丙酸甲酯转化率为96.0%和1,3-丙二醇选择性为84.3%，1,3-PDO的总收率达80.9%。这是目前在高液时空速0.10h^-1的条件下取得的最佳结果。

关键词: 3-羟基丙酸甲酯, 加氢, 1,3-丙二醇, 铜/二氧化硅, Zr改性