Electrostatic adsorption-microwave synthesis of palladium nanoparticles on graphene for improved cross-coupling activity
Electrostatic adsorption-microwave synthesis of palladium nanoparticles on graphene for improved cross-coupling activity
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DOI：
10.1016/j.apcata.2017.11.007
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发表时间：
2018-01-25
影响因子：
5.5
通讯作者：
Gupton, B. F.
中科院分区：
文献类型：
--
作者：
Gilliland, S. E., III;Tengco, J. Meynard M.;Gupton, B. F.
石墨烯材料作为催化剂载体已经显示出改善催化活性的巨大前景。由石墨烯缺陷支撑的Pd纳米颗粒已被证明可以提高Suzuki反应的催化活性，但了解它们的形成和影响它们形成的因素仍然是难以捉摸的。为了更好地理解这一现象，开发了一种新的合成方法，结合强静电吸附法定向离子Pd前体吸收与新的无溶剂微波辐射方法，同时形成Pd纳米颗粒和石墨烯缺陷位点。使用这种新的方法，微波功率低，反应时间短，在大气条件下，并且不使用还原剂或溶剂，获得比商业钯-碳催化剂高一个数量级的催化活性。系统地比较了由四种不同石墨烯材料和两种不同Pd前体合成的催化剂，揭示了Pd-石墨烯缺陷通过三种途径形成，这三种途径受石墨烯载体的初始氧含量和离子Pd前体的选择的影响。
Graphene materials as catalyst supports have shown tremendous promise for improving catalytic activity. Pd nanoparticles supported by graphene defects have been shown to improve catalytic activity in Suzuki reactions, but understanding their formation and factors that affect their formation is still elusive. In order to gain a better understanding of this phenomenon, a new synthetic method was developed combining strong electrostatic adsorption method for directed ionic Pd precursor uptake with a new solventless microwave irradiation method to simultaneously form Pd nanoparticles and graphene defect sites. Catalytic activities an order of magnitude higher than commercial Pd-carbon catalysts were obtained using this new method with low microwave powers, short reaction times, under atmospheric conditions, and without the use of reducing agents or solvents. The systematic comparison of catalysts synthesized from four different graphene materials and two different Pd precursors revealed Pd-graphene defects form through three routes that are affected by the initial oxygen content of graphene support and choice of ionic Pd precursor.