Title : Carbon encapsulated Cu(at)GO catalysts and its application in ethylene carbonate hydrogenation
Abstract:
ncreasing CO2 emission attracts much interest and attention on CO2 hydrogenation to methanol. Ding et al found a process for indirect hydrogenation of CO2 via ethylene carbonate (EC) intermediate to yield methanol with ethylene glycol as the co-product, and meanwhile the obvious advantage of the aim reaction is the high atom economy. In our previous study, Cu@SiO2 has exhibited relatively high activity with the excellent stability, while the stable mechanism needs to be studied further. Therefore, it is highly desirable to develop more effective and stable heterogeneous catalysts for EC hydrogenation and its stable mechanism. In this work, the stable carbon-encapsulated Cu@GO ctalysts with disorder nanoporous network of graphite oxide were prepared by a facile, novel and brief ultrasonic hydrolysis method and the corresponding TEM image was shown in Figure 1a. The as-prepared Cu@GO catalyst was successfully employed in the hydrogenation of ethylene carbonate derived from CO2 . The evaluation results of Cu@GO catalytic reusability verified that the catalytic activity was promoted obviously. Especially, the mentioned method was verified an effective method for fabricating the high dispersity carbon-encapsulated Cu@C catalysts with 20-130 nm Cu particles. Moreover, the TG/DTG result shown in Figure 1b suggested that the special amount residual carbon in Cu@GO catalysts. Figure 1 a) TEM image of Cu@GO catalyst, b) TG/DTG curve of the dried precursor of Cu@GO catalyst under pure nitrogen atmosphere. The evaluation results of catalytic performance suggested that the disorder nanoporous network of graphite oxide promoted the catalytic activities in some extent, with a higher methanol selectivity of 80%, and enhanced the stability of copper-based catalysts. Furthermore, the synergistic effect between the Cu+ and metallic Cu0 species was considered to be the crucial for attaining catalysts with better catalytic activity.
