OMS-2 Catalysts for Formaldehyde Oxidation: Effects of Ce and Pt on Structure and Performance of the Catalysts

Abstract

OMS-2 (2 9 2 type octahedral molecular sieve) and cerium doped OMS-2 were synthesized by refluxing method. The platinum doped on both samples was prepared by impregnation method for catalytic oxidation of formaldehyde. These catalysts were characterized by BET, XRD, SEM, H 2 -TPR and Laser Raman. Results show that OMS-2 formed needle-shape nanocrystal structure. The addition of Ce before the formation of the OMS-2 structure obstructs the process due to mismatch of the cation size. Rather than into the framework of the structure, the addition of Pt after the formation of the OMS-2 structure was loaded on the surface of catalysts, which strongly influenced the bonding of the Mn-O lattice of OMS-2. The properties of the catalyst structure determine the temperature of complete oxidation of HCHO while Pt promotes this reaction at a lower temperature range due to active surface oxygen species and lattice defects.

Structural and chemical disorder of cryptomelane promoted by alkali doping: Influence on catalytic properties

“…7) support this hypothesis: the doped samples are easier to reduce than the original material. This effect was also observed in previous studies [40,41]. In particular, Wang and Li studied the effect of platinum on the properties of cryptomelane, and found that the reducibility of this material clearly increased, due to the formation of lattice defects [41].…”

Complete oxidation of formaldehyde at ambient temperature over supported Pt/Fe2O3 catalysts prepared by colloid-deposition method

“…Great efforts have been made to reduce the indoor emission of HCHO for satisfying the stringent environmental regulations. As one of the most attractive approach, low-temperature catalytic oxidation of formaldehyde (HCHO) to CO 2 and H 2 O has received considerable attention [1][2][3][4][5][6][7][8][9][10][11][12][13]. A variety of catalysts, such as transition metal oxides [12,13], composite oxides [1], and supported noble metals have been used for this process [2][3][4][5][6][7][8][9][10][11].…”

“…Recently, significant progresses on decreasing the reaction temperature of HCHO oxidation have been achieved over supported Pt catalysts [3][4][5][6]11]. For instance, Zhang et al [3,4] reported that a highly active Pt/TiO 2 catalyst, prepared by impregnation method, could completely oxidize HCHO even at ambient temperature.…”

The variation of cationic microstructure in Mn-doped spinel ferrite during calcination and its effect on formaldehyde catalytic oxidation

“…The feed gas was 0.15 ± 0.01 vol.% HCHO balanced with air (1500 ± 100 mL m −3 ). The high concentration of HCHO used in this study was to simulate the removal of industrial formaledehyde [24][25][26]. Gaseous HCHO was generated by flowing dry air over the paraformaldehyde heated at 50 • C. The total flow rate was 100 mL min −1 .…”