ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Room temperature oxidation of gaseous formaldehyde over silver-doped manganese oxide catalyst

Munzar Badshah, Shozab Mehdi, Kamran Alam, Khurram Imran Khan, Imran Abbas, Lorenzo Iezzi, Valentina Segneri, and Marco Stoller

Department of Chemical Engineering, Ghulam Ishaq Khan Institute of Engineering Sciences and Technology, Topi, Pakistan

E-mail: kamran.alam@uniroma1.it

Received: 6 May 2023  Accepted: 4 March 2024

Abstract:

A wide amount of existing building materials and consumables contains formaldehyde (HCHO) that may be released as a gas even after installation. The produced gas may concentrate in housing and offices, leading to a long-term exposure of the occupants. Living in such an environment, even at low concentrations less than 0.5 ppm, may lead to carcinogenic effects and damages of the human central nervous system. As a consequence, the development of methods that oxidize and neutralize the formaldehyde at ambient temperature is welcome. The catalytic oxidation method at ambient temperature is preferred over other available techniques due to its ease of operation and high efficiency. In this work, different weight percentages, ranging from 1 up to 5%, of silver-doped manganese oxides (Ag/MnO_x) were synthesized by a co-precipitation process followed by a calcination at 450 °C for 4 h. The XRD and BET analysis results show that the sample at 4% wt of Ag doped in the MnO_x matrix exhibit highest crystallinity, surface area and highest dispersion values, very near to theoretical ones. The removal performance of HCHO was tested in a silicon wool bed continuous flow reactor characterized by an inner diameter of 4 mm and a length of 12.5 cm. At ambient temperature a removal efficiency and an amount of produced CO₂ of 94% and 66%, respectively.

Keywords: Formaldehyde; MnOx; Catalytic oxidation; Co-precipitation

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-024-03397-3

Chemical Papers 78 (7) 4383–4393 (2024)