Catalytic Performance and in Situ Surface Chemistry of Pure α-MnO2 Nanorods in Selective Reduction of NO and N2O with CO

Search of catalysts made of nonprecious metal for reduction of nitric oxide is important for having a sustainable environment. Catalytic performances of α-MnO 2 nanorods in reduction of nitric oxide and nitrous oxide by carbon monoxide were investigated. Surface chemistry of α-MnO 2 catalyst during catalysis was tracked with ambient pressure X-ray photoelectron spectroscopy. Correlation between catalytic performance and the corresponding in situ surface chemistry during catalysis revealed that Mn 3+ ions and oxygen vacancies are active catalytic sites. Bulk phase of α-MnO 2 nanorods below the catalyst surface is restructured to Mn 3 O 4 in catalysis. Kinetics studies suggested that the reduction of nitric oxide with CO is performed through the formation of the intermediate N 2 O with a followed dissociation to N 2 . This study suggested restructuring of transition metal oxides can tune catalytic performance and even develop catalysts.