Sodium doped SrTi1-xBxO3 (B[dbnd]Mn, Co) for formaldehyde catalytic oxidation: Flame spray pyrolysis fabrication and reaction mechanism elaboration

Abstract

Perovskite oxides are considered to be cheap replacement for precious metal catalysts thanks to its outstanding stability and adjustable catalytic activity. However, the high-demand preparation process still impedes the utilization of catalytic oxidation on perovskite material. Herein, the flame spray pyrolysis (FSP) technology has been utilized to successfully prepare the alkali metal and transition metal co-doped SrTiO3 perovskite catalyst for excellent formaldehyde catalytic performance. The results demonstrate that, compared with alone cobalt dopant, the perovskite doping with Na and Co exhibits significantly larger specific surface area (SSA), better low-temperature reducibility, higher adsorbed oxygen ratio and Co element dispersion, all of which extremely promote the formaldehyde oxidation activity. Additionally, by raising the dispersed gas flow rate to 6 mL/min, Sr0.9Na0.1Ti0.5B0.5O3 presents more outstanding activity of HCHO oxidation reaction. Interestingly, Na doped SrTi0.5Co0.5O3 sample can dramatically enhance formaldehyde catalytic oxidation thermodynamically and kinetically.