形貌调控TiO2负载Cu催化剂对草酸二甲酯选择性加氢制乙醇酸甲酯的影响OA

As a crucial chemical intermediate,methyl glycolate(MG)has extensive applications in fields such as pharmaceuticals and fine chemicals.The route for preparing MG through the hydrogenation of dimethyl oxalate(DMO)using syngas as the raw material has green development concept and boasts high growth potential.Cu-based catalysts exhibit good catalytic performance in DMO hydrogenation reaction but tend to induce deep hydrogenation.To achieve the synergistic optimization of efficient DMO conversion and selective MG synthesis,TiO2 with different morphologies were prepared as the supports firstly,and then a series of Cu-based catalysts(Cu/TO-Nx)were fabricated via the ultrasonic impregnation method.The obtained supports and catalysts were characterized by SEM,N2 physical adsorption/desorption,XRD and so on,and the catalytic performances of Cu/TO-Nx in DMO hydrogenation to MG were investigated.The results demonstrate that support with nanosheet structure(TO-NF)possesses the highest defect degree and the fewest acidic sites,which are conducive to the uniform dispersion of Cu species and the inhibition of side reactions.The Cu/TO-NF catalyst has the highest proportion(n(Cu0)/n(Cu0+Cu+))of Cu⁰ species at 74.80%,with Cu0 particle size of 5.45 nm,and there exists an electronic interaction between the Cu species and TO-NF.Under the reaction conditions of temperature of 230℃,pressure of 2.5 MPa,weight hourly space velocity of 0.7 h-1 and n(H2)/n(DMO)of 30,the DMO conversion rate,MG selectivity and MG yield of Cu/TO-NF can reach 87.73%,82.38%and 72.27%,respectively.Moreover,the catalytic performance of Cu/TO-NF can remain basically stable after 550 h continuous reaction under the aforementioned conditions.