Crystal structure, redox properties and catalytic performance of Ga-based mixed oxides for NO reduction by C3H6

A comparative study between LaGa1−xCuxO3 perovskites and ZnGa2O4 was conducted to clarify the correlation between crystal structure and redox properties as well as catalytic performance for the reduction of NO by C3H6. The oxidation ability of the prepared catalysts decreases following the order LaGa0.8Cu0.2O3 > LaGaO3 > ZnGa2O4. Perovskites, with the general composition of LaGa1−xCuxO3, were found to be suitable materials for NO reduction under scarce oxygen conditions, whereas excess oxygen (O2 > 1%) led to a significant decline in N2 yield. On the contrary, the presence of O2 is necessary for NO conversion to N2 over the ZnGa2O4 spinel, whose SCR activity was moderately enhanced at higher oxygen concentrations. The poor oxidation ability of ZnGa2O4 makes it as a promising candidate for lean NO reduction.