Shi Jin, Jiang Jianzhong
The Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical & Material Engineering, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China.
Langmuir. 2024 Oct 1;40(39):20416-20427. doi: 10.1021/acs.langmuir.4c01784. Epub 2024 Sep 18.
The utilization of Pickering emulsions in interfacial catalysis offers a promising environmental platform for biphasic reactions. However, complicated surface coating or chemical grafting methods are always required to prepare the surface-active catalysts for the Pickering emulsions, since most of them are commercially unavailable. Here, we report CO-switchable Pickering emulsions for biphasic reactions, in which Pd@AlO nanoparticles are in situ modified by a CO/N responsive surfactant. Compared with the chemical grafted methods, the in situ formed Pickering interfacial catalysts avoid complex chemical modification. Furthermore, efficient demulsification and separation of the oil phase and the products without surfactant contaminations can be achieved by CO trigger. The Pickering interfacial catalysis system can also be reformed after the aqueous phase containing the catalyst nanoparticles, and the surfactant is recycled and reused. The strategy is universal for nitrobenzene reductions and alcohol oxidations, providing a convenient and green method for the preparation of Pickering catalysts with commercially available nanoparticles, efficient emulsion separation, and recovery of the catalyst nanoparticles and emulsifiers in various two-phase organic reactions.
皮克林乳液在界面催化中的应用为双相反应提供了一个有前景的环境平台。然而，由于大多数表面活性催化剂在商业上无法获得，制备用于皮克林乳液的表面活性催化剂总是需要复杂的表面涂层或化学接枝方法。在此，我们报道了用于双相反应的CO可切换皮克林乳液，其中Pd@AlO纳米颗粒通过CO/N响应性表面活性剂原位改性。与化学接枝方法相比，原位形成的皮克林界面催化剂避免了复杂的化学修饰。此外，通过CO触发可以实现油相和产物的高效破乳和分离，且无表面活性剂污染。含有催化剂纳米颗粒的水相后，皮克林界面催化体系也可以进行重整，表面活性剂可循环再利用。该策略对于硝基苯还原和醇氧化是通用的，为在各种两相有机反应中用市售纳米颗粒制备皮克林催化剂、高效乳液分离以及回收催化剂纳米颗粒和乳化剂提供了一种方便且绿色的方法。
