Adlayer Structure of and Electrochemical O_2 Reduction on Cobalt Porphine-Modified and Cobalt Octaethylporphyrin-Modified Au(lll) in HClO_4

摘要

Adlayers of cobalt(II) porphine (CoP) and [2,3,7,8,12,13,17,18-octaethyl-21H,23-H-porphine]cobalt(II) (CoOEP) were formed on Au(ll1) by immersing the substrate in a benzene solution containing either CoP or CoOEP molecules and investigated in 0.1 M HC1O_4 by using in situ scanning tunneling microscopy.Highly ordered arrays of CoP were observed on the Au(lll)-(lx 1) surface under controlled potential conditions.The adlayer of CoOEP molecules was also highly ordered,whereas the Au(lll) substrate was found to become reconstructed upon adsorption of CoOEP.Both CoP and CoOEP molecules were closely packed on Au(lll).On the adlayers of CoP and CoOEP,the electrochemical reduction of O2 was examined in 0.1 M HC1O_4 saturated with O_2.The adlayers of both CoP and CoOEP on Au(lll) enhanced the reduction of O_2.