Catalysis of hydrogen evolution on Pt(111) by absorbed hydrogen.

The activity of Pt(111) electrodes for the hydrogen evolution reaction (HER) in 0.5M HSO solution is found to increase with continuous potential cycling in the HER potential region. In addition, the basic cyclic voltammograms obtained in 0.

The Pre-exponential Factor in Electrochemistry.

Like many branches of science, not to mention culture in general, electrochemistry has a number of recurring topics: Areas of research that are popular for a certain time, then fade away as their possibilities seem to have been exhausted, only to return decades later as progress in experimental or theoretical techniques offer new possibilities for their investigation. A prime example are fuel cells, which have undergone five such cycles, but here we discuss a general concept of kinetics-the pre-exponential factor of a rate constant-which has undergone two such cycles. The first cycle was in the 1950-1980s, when the methods of electrochemical kinetics were developed, and the interpretation was based on transition-state theory.

Mechanistic and kinetic implications on the ORR on a Au(100) electrode: pH, temperature and H-D kinetic isotope effects.

pH, temperature and H-D kinetic isotope effects (KIEs) on the ORR on Au(100) have been examined systematically using a hanging meniscus rotating disk electrode system. We found that for the cases with pH > 7, the ORR mainly goes through a 4-electron reduction to OH(-) at E > pzc (potential of zero charge) without any pH and H-D KIEs. When the pH at the electrode/electrolyte interface (pH(s)) is below 7, O2 only reduces to H2O2, its activity increases with pH(s), and a H-D KIE of above 2 is observed in 0.