Li Fengjiao, Wang Liguo, Xiaojin Han
May 9, 2016
Citations
0
Influential Citations
26
Citations
Journal
RSC Advances
Abstract
Hydrogenation of ethylene carbonate (EC) is an attractive and promising approach for indirect hydrogenation of CO2 to co-produce ethylene glycol (EG) and methanol (MeOH). In this work, thermodynamics of EC hydrogenation was firstly calculated, and the results disclosed that EC hydrogenation is exothermic (ΔrHθm = −71.59 kJ mol−1) and thermodynamically favorable (ΔrGθm = −25.62 kJ mol−1). The mesoporous silica supported copper catalysts were successfully prepared by facile ammonia evaporation method using KIT-6, MCM-41 and SBA-15 as support materials. The as-prepared Cu/KIT-6, Cu/MCM-41 and Cu/SBA-15 were thoroughly characterized by N2 physisorption, ICP-AES, N2O titration, FT-IR, XRD, H2-TPR, TEM, XPS and XAES. It was found that copper nanoparticles were well dispersed on these supports. Interestingly, a larger metallic Cu surface area with higher dispersion was obtained on SBA-15 when compared with KIT-6 and MCM-41. Furthermore, Cu0 and Cu+ species in various ratios were verified to co-exist on the surfaces of the three catalysts, which originated from CuO and copper phyllosilicate, respectively. The catalytic performances showed that Cu/SBA-15 exhibited a superior catalytic activity with a TON of 22.0 and 11.4 (mol mol−1) towards EG and MeOH, respectively. Importantly, 100% of EC conversion, 94.7% of EG yield and 62.3% of MeOH yield were achieved within a short reaction time of 4 h over Cu/SBA-15 under optimized conditions. The synergetic effect between Cu0 and Cu+ species, in which it was proposed that Cu0 species dissociated H2, while Cu+ species absorbed the carbonyl group of EC, was responsible for the higher catalytic activity of Cu/SBA-15.