Kinetics of thiocyanate orientation conversion on Pt surface studied by in situ step-scan time-resolved microscope FTIR spectroscopy
Zhou, Z. Y.
Sun, S. G.
- 化学化工－已发表论文 
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 mu 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 (4x10(3) s(-1)) of conversion from N-to S-bounded adsorption is nearly double to that of the reverse process (2x10(3) s(-1)). The difference in kinetics of two processes may be explained through the hard-soft acid-base principle.