Post-etching method using dilute acid solutions is an effective technology to modulate the surface compositions of metal-oxide catalysts.Here theα-MnO_(2) catalyst treated with 0.1 mol/L nitric acid exhibits higher o...Post-etching method using dilute acid solutions is an effective technology to modulate the surface compositions of metal-oxide catalysts.Here theα-MnO_(2) catalyst treated with 0.1 mol/L nitric acid exhibits higher ozone decomposition activity at high relative humidity than the counterpart treated with acetic acid.Besides the increases in surface area and lattice dislocation,the improved activity can be due to relatively higher Mn valence on the surface and newly-formed Brønsted acid sites adjacent to oxygen vacancies.The remnant nitro species deposited on the catalyst by nitric acid treatment is ideal hydrophobic groups at ambient conditions.The decomposition route is also proposed based on the DRIFTS and DFT calculations:ozone is facile to adsorb on the oxygen vacancy,and the protonic H of Brønsted acid sites bonds to the terminal oxygen of ozone to accelerate its cleavage to O_(2),reducing the reaction energy barrier of O_(2) desorption.展开更多
基金supported by the National Natural Science Foundation of China(Nos.22206155 and T2341002)the Fundamental Research Funds for the Central Universities of China(Nos.2682022CX035 and 2682022KJ035)+2 种基金China Postdoctoral Science Foundation(Nos.2022M712632 and 2023T160547)Sichuan Science and Technology Program(No.2023JDRC0066)the State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex(No.SCAPC202109).
文摘Post-etching method using dilute acid solutions is an effective technology to modulate the surface compositions of metal-oxide catalysts.Here theα-MnO_(2) catalyst treated with 0.1 mol/L nitric acid exhibits higher ozone decomposition activity at high relative humidity than the counterpart treated with acetic acid.Besides the increases in surface area and lattice dislocation,the improved activity can be due to relatively higher Mn valence on the surface and newly-formed Brønsted acid sites adjacent to oxygen vacancies.The remnant nitro species deposited on the catalyst by nitric acid treatment is ideal hydrophobic groups at ambient conditions.The decomposition route is also proposed based on the DRIFTS and DFT calculations:ozone is facile to adsorb on the oxygen vacancy,and the protonic H of Brønsted acid sites bonds to the terminal oxygen of ozone to accelerate its cleavage to O_(2),reducing the reaction energy barrier of O_(2) desorption.
