Ag@Cu2O纳米立方体核壳结构对光助丙烯氧化反应的影响

Influence of Ag@Cu2O nanocube core-shell structure on the photo-assisted propylene oxidation

传统的丙烯氧化反应的生产工艺复杂并且会带来大量污染废弃物,相比之下丙烯与氧气直接进行氧化反应具有很大的优势.然而,关于如何提高这种丙烯氧化反应的催化效率的报道较少.该文以Ag纳米立方体为种子,通过外延生长成功构建了具有核壳结构的Ag@Cu2O纳米立方体,研究了其核壳结构对光助丙烯氧化反应的影响.催化测试结果表明,Cu2O壳层有效抑制了丙烯的过度氧化,提高了丙烯醛的选择性.此外,Ag@Cu2O核壳结构不仅有助于Cu2O壳层的光生电子-空穴的高效分离,而且还可以充分利用内核Ag的表面等离子体共振效应提高局部反应温度.因此,这种核壳型催化剂能够有效地利用光来提高丙烯氧化的反应速率.

The direct oxidation of propylene to propylene oxides,such as acraldehyde,using molecular oxygen has many advantages over traditional processes that usually produce a large number of side products and require complex purification equipments.However,how to improve the catalytic efficiency of catalysts in the propylene oxidation reaction is still a great challenge.In this study,we successfully fabricated Ag@Cu2O core-shell heterostructure catalysts via the epitaxial growth of Cu2O on Ag nanocubes and studied their catalytic performances in the propylene oxidation reaction.Catalytic test results showed that the Cu2O shell efficiently suppressed the reaction of excessive oxidation of propylene and improved the selectivity of acrolein. Moreover, we found that the Ag@Cu2O core-shell heterostructure not only contributed to the efficient separation of photogenerated electron-hole in the Cu2O shell, but also made full use of the surface plasmon resonance effect of Ag core to elevate the local reaction temperature.As a result,this core-shell catalyst can effectively ultilize light to improve the reaction rate of propylene oxidation.