Kinetics of thiocyanate orientation conversion on Pt surface studied by in situ step-scan time-resolved microscope FTIR spectroscopy  

作　　者：ZHOU ZhiYou TIAN Na SUN ShiGang 

机构地区：[1]State Key Laboratory for Physical Chemistry of Solid Surfaces,Department of Chemistry,College of Chemistry and Chemical Engineering,Xiamen University

出　　处：《Chinese Science Bulletin》2013年第6期622-626,共5页

基　　金：supported by the National Natural Science Foundation of China (21073152,20833005,20933004,and 21021002);the Fundamental Research Funds for the Central Universities (2010121021 and2012121019);Program for New Century Excellent Talents in University(NECT-11-0301);Outstanding Young Scientific Talents Cultivation Plan of Colleges in Fujian Province (JA10003)

摘　　要：Fast surface dynamic processes of thiocyanate adsorbed on a nanostructured Pt microelectrode were studied by in situ step-scan time-resolved microscope FTIR spectroscopy(in situ SSTR-MFTIRS) at a time resolution of 100 s.It was found that SCN adsorbs preferentially on Pt surface through N atom at low potential,while through S atom at high potential.The potential-induced orientation conversion between N-and S-bounded forms is very reversible,and occurs only within 2 ms after potential alternation.However,the rate constant(4*103s-1) of conversion from N-to S-bounded adsorption is nearly double to that of the reverse process(2*103s-1).The difference in kinetics of two processes may be explained through the hard-soft acid-base principle.Fast surface dynamic processes of thiocyanate adsorbed on a nanostructured Pt microelectrode were studied by in situ step-scan time-resolved microscope FTIR spectroscopy （in situ SSTR-MFTIRS） at a time resolution of 100 μs. It was found that SCN-adsorbs preferentially on Pt surface through N atom at low potential, while through S atom at high potential. The poten- tial-induced orientation conversion between N- and S-bounded forms is very reversible, and occurs only within 2 ms after poten- tial alternation. However, the rate constant （4×10^3s^-1） of conversion from N- to S-bounded adsorption is nearly double to that of the reverse process （2×10^3s^-1））. The difference in kinetics of two processes may be explained through the hard-soft acid-base prin- ciple.

关 键 词：FTIR光谱仪 时间分辨率 电极表面 步进扫描 硫氰酸盐 显微镜 动力学 原位 

分 类 号：O611.3[理学—无机化学]