Au基MOFs双功能催化剂的制备及其催化CO2与苯胺/H2反应性能

以UiO-66(Zr)、MIL-100(Fe)、MIL-100(Cr)、MIL-101(Cr)、NH 2-MIL-101(Al)为载体,Au为活性组分,制备Au/UiO-66(Zr)、Au/MIL-100(Fe)、Au/MIL-100(Cr)、Au/MIL-101(Cr)、Au/NH 2-MIL-101(Al)双功能催化剂。采用XRD、BET、NH 3-TPD、HRTEM等表征催化剂的结构,在釜式反应器中评价催化剂对CO 2与苯胺/H 2反应生成N-甲基苯胺与N,N-二甲基苯胺的N-甲基化反应性能,考察反应条件对催化剂催化性能的影响。结果表明,催化剂的XRD特征衍射峰与相应MOFs的模拟特征峰基本一致;负载Au后催化剂仍具有高的比表面积和大的孔容、孔径;不同MOFs负载Au的催化剂具有不同的酸强度和酸量;Au纳米粒子的分散性很好,粒径为(3~7)nm。制备的催化剂均具有催化CO2与苯胺/H2的N-甲基化反应性能,其中质量分数2%Au/MIL-101(Cr)催化剂催化性能最好,苯胺转化率为45.26%,N-甲基苯胺和N,N-二甲基苯胺选择性分别为73.50%和26.50%,重复使用性能优异。

Preparation of Au-based MOFs bifunctional catalyst and its catalytic performance for reaction of CO2 with aniline /H2

Au/UiO-66(Zr),Au/MIL-100(Fe),Au/MIL-100(Cr),Au/MIL-101(Cr),and NH₂-MIL-101(Al) bifunctional catalysts were prepared by using UiO-66(Zr),MIL-100(Fe),MIL-100(Cr),MIL-101(Cr),NH₂-MIL-101(Al) as carriers and Au as active components.The structure of the catalysts were characterized by XRD,BET,NH₃-TPD and HRTEM.The catalyst was evaluated in reaction of CO₂ with aniline/H₂ in a kettle reactor to form N-methylaniline and N,N-dimethylaniline.The effects of reaction conditions on catalyst activity were investigated.The results showed that the XRD characteristic diffraction peaks of the catalysts were basically consistent with the simulated characteristic peaks of the corresponding MOFs.The catalysts still had high specific surface area,large pore volume and pore diameter after Au loading.The catalysts of Au loaded on different MOFs had different acid strength and acid amount.The dispersion of Au nanoparticles was very good and the particle size distribution was (3-7) nm.The prepared catalysts all had catalytic activity for N-methylation of CO₂ with aniline/H₂.Among them,the performance of 2wt%Au/MIL-101(Cr) catalyst was the best,conversion of aniline was 45.26%,selectivities of N-methylaniline and N,N-dimethylaniline were 73.50% and 26.50%,respectively.