Nano-structural investigation of Ag/Al2O3 catalyst for selective removal of O2 with excess H2 in the presence of C2H4

Ag/γ-Al2O3 catalysts have been characterized in-depth during different thermo-chemical treatments by in situ diffuse reflectance UV–visible spectroscopy and quasi in situ Transmission Electron Microscopy. The combination of these techniques indicates that sintering and redispersion of silver is clearly observed from the increases and decreases in the absorption band intensity over the range of 250–600 nm due to the presence of silver clusters and silver nanoparticles. These results allow us to study the effect of the reaction feed on the metal dispersion at different operation conditions and discuss the formation of active sites during the selective catalytic reduction of O2 with excess H2 in the presence of unsaturated hydrocarbons. In this case high catalytic activity and selectivity toward the oxygen removal was achieved for this catalyst.

Graphical abstract. Ag/γ-Al2O3 is a very active and highly selective catalyst toward the oxygen removal with excess H2 in the presence of unsaturated hydrocarbons. In situ diffuse reflectance UV–visible spectroscopy and quasi in situ TEM were used to study the sintering/redispersion of the metal during different thermo-chemical treatments. The effect of the reaction feed on the metal dispersion and the formation of active sites is also discussed.Figure optionsDownload full-size imageDownload high-quality image (116 K)Download as PowerPoint slideResearch highlights▶ In situ catalyst characterization by diffuse reflectance UV-visble. ▶ Silver catalyst for selective removal of oxygen. ▶ Ethene purification.▶ Quasi in situ TEM characterization of solids.