La compounds photoelectron spectra calibration using La 4d5/2 peak as internal standard is proposed. This is demonstrated by characterizing different La compounds formed after in situ treatments on a nanorod La2O3 catalyst.

Oxidative coupling of methane (OCM) is a catalytic partial oxidation process that converts methane directly to valuable C2 products (ethane and ethylene). The main difficulties from further investigation of this reaction are due to the nature of its high operating temperature and the severe reaction exothermicity. In this work, an especially designed online characterization setup is applied for this reaction, which achieved both precise bed temperature control and real-time product measurement. High-resolution temperature-dependent product rates of OCM (CO2, ethane, and ethylene) were obtained, and their behavior vs reaction conditions as well as the activation energy barriers above their onset temperatures are clearly differentiated over a recently reported high performance nanorod La2O3 catalyst. Different from general expectation, CO2, resulting from full methane oxidation, dominates all the products in the lower temperature region, whereas the C2 species are only formed at much higher temperatures. Further analysis indicates that the selectivity and apparent activation energy for both CO x and C2 products are strongly influenced by the oxygen concentration and temperature. In combination with density functional theory calculations and additional experimental measurements, significant insights are brought to this high-temperature reaction of wide interest.

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A Knoevenagel condensation reaction between benzaldehyde and ethyl cyanoacetate was performed in the liquid phase under mild and solventless conditions using a series of catalysts modified by impregnating magnesium and barium cations on different supports (SiO, ZnO, γ-AlO and FeO). The highest reaction rates and yields (after 6 hours) were observed using ZnO which possessed the highest concentration of acidic and basic sites, as determined by TPD-MS. In situ FTIR experiments show that the adsorption of ethyl cyanoacetate on ZnO results in an increase of hydroxyl intermediate species on the ZnO surface. There is evidence to suggest that the reaction proceeds via an autocatalytic pathway, as an induction period was observed before the observed catalytic activity. It was also found that both surface acidic and basic sites are necessary to obtain high rates of the catalytic reaction. By comparing the catalytic activity with the catalyst surface basicity, we are able to determine the optimum proportion of acid and base sites necessary to obtain the highest reaction rates.