The practical utility of ternary nickel-cobalt-manganese oxide-supported platinum catalysts for room-temperature oxidative removal of formaldehyde from the air

Yongbiao Hua; Kumar Vikrant; Ki-Hyun Kim; Philippe M Heynderickx; Danil W Boukhvalov

doi:10.1016/j.jcis.2024.04.005

The practical utility of ternary nickel-cobalt-manganese oxide-supported platinum catalysts for room-temperature oxidative removal of formaldehyde from the air

J Colloid Interface Sci. 2024 Jul:665:1029-1042. doi: 10.1016/j.jcis.2024.04.005. Epub 2024 Apr 2.

Authors

Yongbiao Hua¹, Kumar Vikrant¹, Ki-Hyun Kim², Philippe M Heynderickx³, Danil W Boukhvalov⁴

Affiliations

¹ Department of Civil and Environmental Engineering, Hanyang University, 222 Wangsimni-Ro, Seoul 04763, Republic of Korea.
² Department of Civil and Environmental Engineering, Hanyang University, 222 Wangsimni-Ro, Seoul 04763, Republic of Korea. Electronic address: kkim61@hanyang.ac.kr.
³ Center for Environmental and Energy Research (CEER), Engineering of Materials via Catalysis and Characterization, Ghent University Global Campus, 119-5 Songdo Munhwa-ro, Yeonsu-gu, Incheon 406-840, Republic of Korea; Department of Green Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium.
⁴ College of Science, Institute of Materials Physics and Chemistry, Nanjing Forestry University, Nanjing 210037, China; Institute of Physics and Technology, Ural Federal University, Mira Street 19, 620002 Yekaterinburg, Russia.

PMID: 38579386
DOI: 10.1016/j.jcis.2024.04.005

Abstract

Formaldehyde (FA), a carcinogenic oxygenated volatile organic compound, is present ubiquitously in indoor air. As such, it is generally regarded as a critical target for air quality management. The oxidative removal of FA under dark and room-temperature (RT) conditions is of practical significance. A series of ternary nickel-cobalt-manganese oxide-supported platinum catalysts (Pt/NiCoMnO₄) have been synthesized for FA oxidative removal at RT in the dark. Their RT conversion values for 50 ppm FA (X_FA) at 5,964 h^-1 gas hourly space velocity (GHSV) decrease in the following order: 1 wt% Pt/NiCoMnO₄ (100 %) > 0.5 wt% Pt/NiCoMnO₄ (25 %) > 0.05 wt% Pt/NiCoMnO₄ (14 %) > NiCoMnO₄ (6 %). The catalytic performance of 1 wt% Pt/NiCoMnO₄ has been examined further under the control of various process variables (e.g., catalyst mass, flow rate, relative humidity, FA concentration, time on stream, and molecular oxygen content). The catalytic oxidation of FA at low temperatures (e.g., RT and 60 °C) is accounted for by Langmuir-Hinshelwood mechanism (single-site competitive-adsorption), while Mars van Krevelen kinetics is prevalent at higher temperatures. In situ diffuse-reflectance infrared Fourier-transform spectroscopy reveals that FA oxidation proceeds through a series of reaction intermediates such as DOM, HCOO^-, and CO₃^2-. Based on the density functional theory simulations, the unique electronic structures of the nearest surface atoms (platinum and nickel) are suggested to be responsible for the superior catalytic activity of Pt/NiCoMnO₄.

Keywords: Catalytic oxidation; Formaldehyde; Indoor air; Transition metal oxide; Volatile organic compounds.