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Position:Home > News > Technical Data > the alkaline EG method by microwave irradiation on the reaction
the alkaline EG method by microwave irradiation on the reaction
Source:    Published:2011/6/9 16:44:48

   A novel synthesis method (alkaline ethylene glycol (EG) method) has been proposed for the effective prep aration of small noble metal and bimetallic nanoclusters (1-3 nm), such as Pt, Rh, Ru [11], Os, Pt/Rh [12] and Pt/ Ru [13,14] nanoclusters, which are stabilized with EG and simple ions. These unprotected metal nanoclusters are very tractable as building blocks for fabricating novel catalytic materials due to the high efficiency of synthesis, the convenience of separation, the flexibility of modification and the controllability of particle size. Recently, Liu

   and co-workers [15] and Gedanken and co-workers [16l, respectively, further improved greatly the synthesis rate of

  

   the alkaline EG method by microwave irradiation on the reaction system. The unprotected Pt, Rh and Ru nanoclusters could be produced within 20-30s using this microwave-assisted alkaline EG synthesis technique. The unprotected metal nanoclusters have been successfully

   applied to the fabrication of highly selective hydrogen sensor [17] and lughly selective catalysts for the hydrogenation of chloronitrobenzene (CNB) [18,19]. Xin and co-workers [20-24] and Mao and Mao [25] have succeeded in preparing promising electrocatalysts for fuel cells with metal loadings of l0-50wt.% by some modifications in the alkaline EG synthesis method.

  

   This chapter will mainly deal with the advantages of the alkaline EG synthesis method for the chemical preparation of noble metal nanoclusters stabilized by EG and simple ions, as well as the excellent performances of the functional materials assembled using these unprotected metal nanoclusters as building blocks. Synthesis Strategy Alkaline Ethylene Glycol Synthesis Method The strategy usually adopted for the chemical preparation of metal nanoclusters is to lead metal atoms produced in

  

   situ to aggregate and generate metal cores, followed by depositing metal atoms on these cores. Due to the huge specific surface energy, small metal particles in colloidal solutions have a great tendency to aggregate and form precipitates in the absence of suitable stabilizers. The charge effect derived from the electrostatic repulsion of adsorbed ions on the small metal particles and the solvent effect, namely decreasing the particles' surface energy by

   adsorbing solvent molecules, have been known to be effective for stabilizing tiny metal nanoclusters in colloidal solutions [3]. A great handicap in the chemical preparation of unprotected metal nanoclusters with small particle

  

  

CAS NO.72468-94-1
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