Enhanced formaldehyde-removal over modified cryptomelane catalysts

• Published in: IOP conference series. Earth and environmental science 2021-12, Vol.947 (1), p.12024
• Main Authors: Tran, Trong-Phu, Ta-Thi, Xuan-Phuc, Nguyen, Kim-Chau, Tran, Duy-Nhan, Nguyen-Phan, Thuy-Duong, Pham, Khanh-Nguyen, Nguyen, Gia-Han, Tran-Thuy, Tuyet-Mai
• Format: Article
• Language: English
• Subjects: Carbon dioxide; Catalysts; Catalytic activity; Cobalt; Copper; Diffraction patterns; Dopants; Formaldehyde; Manganese; Oxidation; Relative humidity; Titration; X-ray diffraction
• ISSN: 1755-1307; 1755-1315
• DOI: 10.1088/1755-1315/947/1/012024

M-OMS-2 materials (M = K + , Cu 2+ , Co 2+ ) were prepared by an uncomplicated reflux method, and the cryptomelane crystalline structure was confirmed by X-ray diffraction patterns. Element analysis recorded ~56 - ~59 wt.% of Mn in the three synthesized samples and ~2.8 wt.% loadings of dopants over Co-OMS-2 and Cu-OMS-2 materials. A titration method valued the average oxidation states of manganese at 3.60, 3.71 and 3.77 for K-OMS-2, Co-OMS-2 and Cu-OMS-2, respectively. In comparison with K-OMS-2, Co and Cu dopants depicted a significant enhancement catalytic activity in removal of formaldehyde at low (5%) and high (65 %) relative humidity (RH). Cu-OMS-2 showed the highest catalyst performance with ~90 % of formaldehyde conversion at 150 °C, 65% RH, whereas only ~40 % (for Co-OMS-2) and ~26 % (for K-OMS-2) of that were observed. The finding results promised a potential Cu-OMS-2 material for designed low-costly catalyst in formaldehyde removal at a wide range of RH.