Magnetic Nanoparticles with In Situ Surface Growing Polymeric Brushes as Reactive Pickering Interfacial Catalysts for Biphasic Reactions
作者：Jun Tang, Xiaobo Liu, Shixiong Cao, Shouhao Zhang, Hao Zhang, Lingyu Zhu, Jianbing Ji, Jianli Wang
關(guān)鍵字：Pickering, Magnetic Nanoparticles
論文來(lái)源：期刊
具體來(lái)源：The Journal of Physical Chemistry C
發(fā)表時(shí)間：2021年
液相-液相(L - L)兩相體系中催化反應(yīng)的強(qiáng)化和液滴控制是本研究的重點(diǎn)。磁性材料的表面工程為磁性皮克林界面催化劑(MPICs)的設(shè)計(jì)提供了一種合理的策略，它在很大程度上彌補(bǔ)了均相催化和多相催化的差距，促進(jìn)了資源的高效和選擇性轉(zhuǎn)化。在本研究中，我們通過(guò)表面引發(fā)可逆加成-斷裂鏈轉(zhuǎn)移(SIRAFT)聚合來(lái)控制有機(jī)堿單體刷的生長(zhǎng)，從而獲得磁聚合納米催化劑Fe3O4@PS-PM。表面工程策略使我們能夠簡(jiǎn)單地調(diào)整表面潤(rùn)濕性和活性位點(diǎn)含量，以控制乳液催化。在雙相反應(yīng)體系(酯交換和環(huán)氧化反應(yīng))中，乳化體系的催化性能是非乳化體系的兩倍以上，這歸因于Pickering乳液微環(huán)境的增強(qiáng)作用。此外，固有的順磁性表明，MPICs可以迅速?gòu)挠退缑娼馕突厥?，并在五次運(yùn)行中表現(xiàn)出良好的催化活性和穩(wěn)定性。該實(shí)用表面工程在磁性可分離PICs的構(gòu)建和調(diào)整方面具有廣闊的前景，并使基于多功能Pickering乳液平臺(tái)的綠色化學(xué)轉(zhuǎn)化易于操作。
The intensification of catalytic reaction and droplet manipulation in a liquid-liquid (L-L) biphasic system has been widely focused in this research. The surface engineering of magnetic materials offers a reasonable tactic for the design of magnetic Pickering interfacial catalysts (MPICs), which substantially bridges the gap of homogeneous and heterogeneous catalysis for promoting efficient and selective transformation of resources. In this study, we control the growth of organic base monomer brushes by surface-initiated reversible addition-fragmentation chain transfer (SIRAFT) polymerization to afford a magneto-polymeric nanocatalysts Fe3O4@PS-PM. The surface engineering strategy enables us to simply tune the surface wettability and active site content for the manipulation of emulsion catalysis. In a biphasic reaction system (i.e., transesterification and epoxidation), the catalytic performance of an emulsion system is more than twice that of an unemulsified system, which is attributed to the enhancement effect of the Pickering emulsion microenvironment. In addition, the inherent paramagnetism demonstrates that MPICs can be swiftly desorbed and recovered from the oil?water interface and showed attractive catalytic activity and stability over five runs. The practical surface engineering has promising prospects for construction and adjustment of magnetically separable PICs and enables accessible manipulation of green chemical transformation based on a versatile Pickering emulsion platform.
DOI:10.1021/acs.jpcc.1c06863
國(guó)家自然科學(xué)基金項(xiàng)目(21374103、22178317)和浙江省自然科學(xué)基金項(xiàng)目(LY18B040004)資助。