Influence of Pd and Rare Earth Metals Oxides (Ce, La) as Modifying Additives in the Co,Ni-Oxide Catalyst Compositions on the Process of Methane Oxidation

NiO-Al2O3 and Co3O4 oxide catalysts modified with palladium and oxides of rare earth metals (Ce and La) and formed on structured cordierite supports have been studied in the process of methane oxidation at different O-2/CH4 ratios. It is shown that methane oxidation proceeds without the formation of CO even at an O-2/CH4 ratio of < 2 (in contrast to nickel-containing catalysts) in the presence of cobalt-containing catalysts modified with cerium and lanthanum oxides. The addition of CeO2 promotes Co3O4 dispersion, increases the number of oxygen vacancies, and prevents agglomeration of the active phase of the catalyst at high temperatures. The modification of Co3O4-CeO2/cordierite with palladium (0.1%) enhances its activity due to increased surface oxygen mobility as a result of the interphase interaction of palladium with cobalt oxides and ceria (according to the TPR-H-2 and XPS data).

Automated summary

NiO-Al2O3 and Co3O4 oxide catalysts modified with palladium and oxides of rare earth metals (Ce and La) and formed on structured cordierite supports were investigated for methane oxidation. It was found that the addition of cerium and lanthanum oxides to cobalt-containing catalysts allowed methane oxidation to proceed without CO formation even at low O2/CH4 ratios. The addition of CeO2 promoted dispersion of Co3O4, increased oxygen vacancies, and prevented agglomeration of the catalyst's active phase. Palladium modification enhanced the activity of the Co3O4-CeO2/cordierite catalyst by increasing surface oxygen mobility through interphase interaction with cobalt oxides and ceria.