Effect of feedstock solvent on the stability of Cu/SiO2catalyst for vapor-phase hydrogenation of dimethyl oxalate to ethylene glycol

Jingdong Lin, Xiaoqin Zhao, Yunhe Cui, Hongbin Zhang, Daiwei Liao
2012 Chemical Communications  
The preparation method of 25wt%Cu/SiO 2 catalysts with 25 wt% copper loadings was described as follows. 9.51 g of Cu(NO 3 ) 2 •3H 2 O (AR) was dissolved in 200 mL of deionized water, and 28% ammonia aqueous solution was then dropped into it. The mixed solution was stirred for 30 min and formed a copper ammonia complex solution with pH value of 10. 25.0 g of silica sol (JN-40, Qingdao Ocean Chemical Engineering Limited Company) was subsequently dropped into the copper ammonia solution and
more » ... solution and stirred for another 30 min, all of which were operated at room temperature. Then, the suspension was preheated at 363 K to evaporate ammonia and deposited the copper species on silica. When pH value of the suspension decreased to 5-6, the evaporation process was terminated. The precipitate was washed with deionized water several times and dried at 393 K overnight. The catalyst precursors were calcined in air at 723 K for 4 h, pelletized, crushed, sieved to 40-60 meshes. The catalytic performance of 25wt%Cu/SiO 2 catalyst for the synthesis of EG was investigated for the continuous vapor-phase hydrogenation of DMO. Prior to the hydrogenation reaction, the 25wt% Cu/SiO 2 catalyst was reduced in H 2 flow at 623 K for 2 h. After cooling to 473 K, 10 wt% DMO-methanol or were fed into the reactor at a H 2 /DMO molar ratio of 80 and a reaction pressure of 3.0 MPa. The liquid hour space velocity (LHSV) of DMO was 0.6 h −1 . The products were Electronic Supplementary Material (ESI) for Chemical Communications This journal is
doi:10.1039/c1cc15783c pmid:22158830 fatcat:vqt2zei3xrcwpbk5cvc3yx45ae