Electrochemically exfoliated graphene as high-performance catalyst support to promote electrocatalytic oxidation of methanol on Pt catalysts

电化学剥离石墨烯作为高性能催化剂载体促进甲醇在铂催化剂上的电催化氧化

Electrochemically exfoliated graphene(EEG)is a kind of high-quality graphene with few oxygen-containing functional groups and defects on the surface,and thereby is more suitable as catalyst support than other carbon materials such as extensively used reduced graphene oxide(rGO).However,it is difficult to grow functional materials on EEG due to its inert surface.In this work,ultra-small Pt nanocrystals(~2.6 nm)are successfully formed on EEG and show better electrocatalytic activity towards methanol oxidation than Pt catalysts on r GO.The outstanding catalytic properties of Pt catalysts on EEG can be attributed to the fast electron transfer through EEG and high quality of Pt catalysts such as small grain size,high dispersibility and low oxidation ratio.In addition,SnO2 nanocrystals are controllably generated around Pt catalysts on EEG to raise the poison tolerance of Pt catalysts through using glycine as a linker.Owing to its outstanding properties such as high electrical conductivity and mechanical strength,EEG is expected to be widely used as a novel support for catalysts.

电化学剥离石墨烯是一种高质量的石墨烯,其表面几乎没有含氧官能团和缺陷,因此比其他碳材料(例如广泛使用的还原氧化石墨烯)更适合作为催化剂载体。然而,由于石墨烯的惰性表面,其功能材料很难在电化学剥离的石墨烯上生长。在这项工作中,超小的Pt纳米晶(~2.6nm)成功地生长在电化学剥离的石墨烯表面,对甲醇氧化的电催化活性优于还原氧化石墨烯负载的Pt催化剂。电化学剥离石墨烯负载的铂催化剂具有优异的电催化性能,这主要归功于电化学剥离石墨烯与铂之间的快速电子转移,同时,电化学剥离石墨烯负载的铂催化剂具有颗粒尺寸小、分散性高、氧化态Pt含量低等优点。此外,利用甘氨酸作为连接剂,在电化学剥离石墨烯上可以控制铂催化剂周围生成SnO2纳米晶,进一步增强铂催化剂的抗中毒能力。电化学剥离石墨烯具有良好的导电性和机械强度,有望作为新型催化剂载体得到广泛应用。