Many catalysts for energy applications such as fuel cell electrocatalysts and Fischer Tropsh synthesis call for bimetallic particles, catalytic activity and stability of which can be increased when a promoter metal is in close interaction with a first metal. However, intimate contact between the two metals is often difficult to achieve because general synthesis methods such as sequential impregnation, co-mulling or coprecipitation lead to inconsistent and random distribution of the metals over the support surface. Thus, the key to producing an effective bimetallic catalyst lies in the intimate metal-metal interaction.
This paper presents a simple, rational method to synthesize bimetallic particles. Via strong electrostatic adsorption (SEA), metal coordination complexes such as Pt and Pd ammines are selectively adsorbed onto a carbon or oxide supported metal oxide such as cobalt oxide, iron oxide, or molybdenum oxide, such that after reduction, bimetallic particles are produced. The selectivity of Pt or Pd adsorption onto the metal oxide rather than support can be determined by EDXS. The dispersion and particle size of the bimetallic particles can be determined by STEM, XRD and TPR.
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