Influence of preparation methods on the activity of macro-structured ball-milled MWCNT catalysts in the ozonation of organic pollutants

• Type: Article in International Scientific Journal
• Date: 2021

Authors

Restivo, J (Author) Other; Carla Orge (Author) FEUP; dos Santos, ASGG (Author) Other; O.S.G.P. Soares (Author) FEUP; Manuel Fernando R Pereira (Author) FEUP

Journal

Title: Journal of Environmental Chemical Engineering

Vol. 9

ISSN: 2213-3437

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 0 Citations

Scopus - 10 Citations

Other information

Authenticus ID: P-00T-H3A

DOI: 10.1016/j.jece.2020.104578

Abstract (EN): A series of macro-structured catalysts consisting of nanostructured layers of mechanically processed multiwalled carbon nanotubes (MWCNT) coated onto cordierite monoliths were prepared using a novel methodology and assessed as catalysts in the ozonation of a model organic pollutant. The often used chemical vapor deposition method for formation of nanostructured layers of carbon materials is, by nature, incompatible with ball-milling or other methods for mechanical or mechano-chemical modification of MWCNT. The preparation method here described was designed to translate the positive effect observed in the performance of ball-milled MWCNT as ozonation catalysts when compared with unmodified MWCNT to macro-structured catalytic systems. The performance of such macro-structured catalysts in the ozonation of organic pollutants is reported and analyzed for the first time. The effect of the preparation methodology, which includes physical functionalization of the MWCNT with a non-ionic surfactant (Triton X-100 (R)), in the performance of the powder catalysts was evaluated. It was found that, for the coated nanostructured layers, the decrease in the expected activity is related to the packing of the materials. Nevertheless, the catalytic nanostructured coated layers were found to compare favorably with a reference sample. Thus, the beneficial effect of ball-milling MWCNT is still retained upon coating, even with a decrease in the intrinsic activity of the powder material. The increase in MWCNT mass in the coated samples introduces diffusion limitations, suggesting that creating a macroporous system in the MWCNT layers might be desirable. The introduction of oxygen-containing surface functionalities improved the long-term stability of the nanostructured catalytic layers.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 10