The mechanism and kinetics of electrocatalytic oxidation of formic acid at Pt electrodes is discussed in detail based on previous electrochemical in-situ ATR-FTIRS data [Langmuir 22, 10399 （2006）and Angewa. Chem. Int. Ed. 50, 1159 （2011）]. A kinetic model with formic acid adsorption （and probably the simultaneous C-H bond activation） as the rate determining step, which contributes to the majority of reaction current for formic acid oxi- dation, was proposed for the direct pathway. The model simulates well the IR spectroscopic results obtained under conditions where the poisoning effect of carbon monoxide （CO） is negligible and formic acid concentration is below 0.1 mol/L. The kinetic simulation predicts that in the direct pathway formic acid oxidation probably only needs one Pt atom as active site, formate is the site blocking species instead of being the active intermediate. We review in detail the conclusion that formate pathway （with either 1st or 2nd order reaction kinetics） is the direct pathway, possible origins for the discrepancies are pointed out.
We study the photodissociation dynamics of nitrous oxide using the time-sliced ion veloc- ity imaging technique at three photolysis wavelengths of 134.20, 135.30, and 136.43 nm. The O（^1Sj=0）＋N2（XI∑g＋） product channels were investigated by measuring images of the O（iSj=0） products. Vibrational states of N2（XI∑g＋） products were fully resolved in the images. Product total kinetic energy releases （TKER） and the branching ratios of vibrational states of N2 products were determined. It is found that the most populated vibrational states of N2 products are v--2 and v--3. The angular anisotropy parameters （8 values） were also derived. The β values are very close to 2 at low vibrational states of the correlated N2 （X1 ∑g＋） products at all three photolysis wavelengths, and gradually decrease to about 1.4 at v--7. This indicates the dissociation is mainly through a parallel transition state to form products at lower vibrational states, and the highly vibrational exited products are from a more bent configuration. This is consistent with the observed shift of the most intense rotational structure in the TKER as the vibrational quantum number increases.
Fast scan voltammetry is an efficient tool to distinguish oxidative/reductive adsorp- tion/desorption from that for bulk reaction. In this work, we provide a methodology that the isotherm of oxidative/reductive adsorption desorption processes at electrode surface can be obtained using just one solution with relatively low reactant concentration, by taking the advantage of varying the potential scan rate （relative of the diffusion rate） to tune the adsorption rate and proper mathematic treatment. The methodology is demonstrated by taking acetate adsorption at Pt（lll） in acidic solution as an example. The possibility for extension of this method toward mechanistic studies of complicated electrocatalytic reactions is also given.
