Effects of doping in 25-atom bimetallic nanocluster catalysts for carbon-carbon coupling r

Effects of doping in 25-atom bimetallic nanocluster catalysts for carbon-carbon coupling reaction of

iodoanisole and phenylacetylene

Zhimin Li;Xiujuan Yang;Chao Liu;Jin Wang;Gao Li

【期刊名称】《自然科学进展（英文版）》 【年(卷),期】2016(026)005

【摘要】We here report the catalytic effects of foreign atoms (Cu, Ag, and Pt) doped into well-defined 25-gold-atom nanoclusters. Using the carbon-carbon coupling reaction of p-iodoanisole and phenylacetylene as a model reaction, the gold-based bimetallic MxAu25?x(SR)18 (–SR=–SCH2CH2Ph) nanoclusters (supported on titania) were found to exhibit distinct effects on the conversion of p-iodoanisole as well as the selectivity for the Sonogashira cross-coupling product, 1-methoxy-4-(2-phenylethynyl)benzene). Compared to Au25(SR)18, the centrally doped Pt1Au24(SR)18 causes a drop in catalytic activity but with the selectivity retained, while the AgxAu25?x(SR)18 nanoclusters gave an overall performance

comparable

to

Au25(SR)18.

Interestingly,

CuxAu25?x(SR)18 nanoclusters prefer the Ullmann homo-coupling pathway and give rise to product 4,4′-dimethoxy-1,1′-biphenyl, which is in opposite to the other three nanocluster catalysts. Our overall conclusion is that the conversion of p-iodoanisole is largely affected by the electronic effect in the bimetallic nanoclusters’ 13-atom core (i.e.,