The Catalytic Oxidation of Formaldehyde by FeOx-MnO2-CeO2 Catalyst: Effect of Iron Modification

Abstract

A series of FeOx-MnO2-CeO2 catalysts were synthesized by the surfactant-templated coprecipitation method and applied for HCHO removal. The influence of Fe/Mn/Ce molar ratio on the catalytic performance was investigated, and the FeOx-MnO2-CeO2 catalyst exhibited excellent catalytic activity, with complete HCHO conversion at low temperatures (40 °C) when the molar ratio of Fe/Mn/Ce was 2/5/5. The catalysts were characterized by N2 adsorption and desorption, XRD, H2-TPR, O2-TPD and XPS techniques to illustrate their structure–activity relationships. The result revealed that the introduction of FeOx into MnO2-CeO2 formed a strong interaction between FeOx-MnO2-CeO2, which facilitated the improved dispersion of MnO2-CeO2, subsequently increasing the surface area and aiding pore development. This promotion effect of Fe enhanced the reducibility and produced abundant surface-active oxygen. In addition, a great number of Oα is beneficial to the intermediate decomposition, whereas the existence of Ce3+ favors the formation of oxygen vacancies on the surface of the catalyst, all of which contributed to HCHO oxidation at low temperatures.

Rare Earth Dopants Enhance Thermocatalytic Activity of Manganese Oxides on Corrugated Silica Carriers for Formaldehyde Degradation

“…[15] Previous works have proved that manganese oxide (MnO 2 ) possesses better low-temperature catalytic activity than other metal oxides including CuO, [12] Co 3 O 4 , [17] FeO x [18] and CeO 2 . [19] However, the narrow band gap between the electron and hole weakens the reaction activity of MnO 2 . [20] Rare earth (RE) ions exhibit various oxidation states and oxygen vacancies, which endow themselves with desirable dopants.…”

“…To overcome the disadvantages of noble metal catalysts such as high costs and poor thermostabilities, [16] the development of transition metal oxides of manganese, copper, iron and cobalt becomes an alternative strategy [15] . Previous works have proved that manganese oxide (MnO 2 ) possesses better low‐temperature catalytic activity than other metal oxides including CuO, [12] Co 3 O 4 , [17] FeO x [18] and CeO 2 [19] . However, the narrow band gap between the electron and hole weakens the reaction activity of MnO 2 [20] .…”

Preparation of a Novel Formaldehyde-Free Impregnated Decorative Paper Containing MnO2 Nanoparticles for Highly Efficient Formaldehyde Removal

“…Among the various methods considered, catalytic oxidation emerges as a highly promising approach due to its ability to efficiently convert HCHO into CO 2 and H 2 O at ambient conditions, while maintaining a low cost and avoiding the generation of toxic byproducts. 11 Dong et al 12 synthesized a series of metal oxide catalysts and studied the sequence of their catalytic activity at 120 °C. The findings indicated that MnO 2 demonstrated the highest conversion rate of HCHO at 80%.…”

A simple method to regulate surface hydroxy groups on Al2O3 for improving catalytic oxidation performance for HCHO on Pt/Al2O3

“…Supported noble metal catalysts fulfill these requirements and are more practical materials compared with transition metal oxide catalysts which oxidize HCHO completely above ambient temperature. [5][6][7] In 2005, the Pt/TiO 2 catalyst was utilized in HCHO oxidation, oxidizing HCHO into CO 2 and H 2 O without any by-products at ambient temperature. 8 Due to the scarcity of noble metals, it is necessary to reduce the content of noble metals to reduce the cost.…”