A surfactant-free method to prepare Pd xAu y bimetallic nanospheres and their application in catalysis

摘要

Recently, bimetallic alloys have drawn more and more attentions owing to their superior catalytic performance towards the monometallic ones. However, in the most of established synthetic approaches, surfactants as structure directing agents were necessary, which resulting in the impurity of alloys and structural sensitivity to their kinds or concentrations. To overcome this drawback, herein, we have introduced a surfactant-free method to prepare PdxAuynanospheres by using ascorbic acid as reducing agent. The as-obtained PdxAuyalloys with atomic ratio of Pd/Au ranging from 1:2 to 2:1 displayed a sphere-like structure. Controlled experiments indicated that an appropriate reducing potential was important for shaping final morphology. The method presented here could be used to prepare PdxAuynanospheres on the various support surface, such as reduced graphene oxide nanosheets and graphitic carbon nitride. Additionally, this versatile method could even be extended to prepare Pt-based bimetallic nanospheres. In catalytic reduction of 4?nitrophenol, bimetallic PdxAuycatalysts displayed better catalytic activity towards monometallic catalysts, and Pd1Au2nanospheres exhibited the best catalytic property.