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Free keywords:
catalysis; Au nanoparticle; diblock copolymer; sintering; CO oxidation; interparticle interaction; size effects; XPS;TPD; AFM
Abstract:
This work aims to get insight into the influence of interparticle interactions on catalysis. The low temperature CO oxidation is used as a model reaction. A strong dependence of the catalytic activity and stability of gold nanoparticles uniformly dispersed on polycrystalline TiC films was observed as a function of the interparticle distance. Two samples with similar height distributions (∼2 nm), but with different average interparticle distances (∼30 and ∼80 nm), were synthesized using diblock copolymer encapsulation. Their chemical reactivity was investigated by temperature programmed desorption (TPD), and reactive coarsening and subsequent deactivation was observed for the sample with the smallest interparticle distance. The system with the largest average interparticle distance showed higher stability towards agglomeration and longer lifetime.