酚醛树脂基介孔碳材料负载Cu-Zn催化合成碳酸二甲酯的研究

Synthesis of dimethyl carbonate over Cu-Zn based catalysts supported on mesoporous carbon from phenol-formaldehyde resin

以新制备的酚醛树脂为炭前驱体,加入不同Cu/Zn比例的硝酸铜-硫酸锌溶液混合,煅烧制备了酚醛树脂基介孔碳材料负载Cu-Zn催化剂,用XRD、XPS、N2吸附/脱附等手段对其进行了表征,并在固定床反应器中考察了其催化二氧化碳和甲醇气相直接合成碳酸二甲酯的性能。结果表明:n(Cu)/n(Zn)=2的Cu-Zn/PF催化剂具有最好的催化性能,其比表面积达459m2·g-1,平均孔径3.44nm,催化剂活性组分均匀地分散在载体上且与载体有明显的强相互作用;该催化剂在反应温度为320℃,反应压力为3.2MPa时,甲醇转化率达98.11%,碳酸二甲酯选择性为95.05%,并有较好的稳定性。

Mesoporous carbon-supported Cu-Zn catalysts were prepared by adding the aqueous solutions of copper nitrate and zinc sulphate with different Cu/Zn atomic ratios to the new prepared phenol-formaldehyde resin and calcination. The catalysts were characterized by XRD, XPS and N2 adsorption/desorption, and their catalytic behaviors in the direct gas phase synthesis of dimethyl carbonate from CO, and methanol were evaluated in a flow fixed-bed reactor. The results showed that the Cu-Zn/PF catalyst with a CufZn atomic ratio of 2 exhibited the best catalytic performance, the specific surface area and average pore size of which were 459m^2. g^-1 and 3.44nm, respectively, and the active component Cu was well dispersed on the surface of the support, and further more, there was a strong interaction between the active component and the support; over the optimized catalyst, under reaction temperature of 320℃ and pressure of 3.2MPa, the conversion of methanol was up to 98.11% with a selectivity to dimethyl carbonate of 95.05%; and the catalyst showed good stability.