Highly N-2-Selective Activated Carbon-Supported Pt-In Catalysts for the Reduction of Nitrites in Water

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

Authors

Olívia Salomé G. P. Soares (Author) FEUP; Erika O. Jardim (Author) Other; Enrique V. Ramos-Fernandez (Author) Other; Juan J. Villora-Picó (Author) Other; M. Mercedes Pastor-Blas (Author) Other; Joaquín Silvestre-Albero (Author) Other; José Melo Orfão (Author) FEUP; Manuel Fernando R. Pereira (Author) FEUP; Antonio Sepúlveda-Escribano (Author) Other

Journal

Title: Frontiers in Chemistry

Vol. 9

Initial page: 11

ISSN: 2296-2646

Publisher: Frontiers Media

Indexing

ISI Web of Knowledge - 0 Citations

Scopus - 4 Citations

Other information

Authenticus ID: P-00V-ADH

DOI: 10.3389/fchem.2021.733881

Abstract (EN): The catalytic reduction of nitrites over Pt-In catalysts supported on activated carbon has been studied in a semi-batch reactor, at room temperature and atmospheric pressure, and using hydrogen as the reducing agent. The influence of the indium content on the activity and selectivity was evaluated. Monometallic Pt catalysts are very active for nitrite reduction, but the addition of up to 1 wt% of indium significantly increases the nitrogen selectivity from 0 to 96%. The decrease in the accessible noble metal surface area reduces the amount of hydrogen available at the catalyst surface, this favoring the combination of nitrogen-containing intermediate molecules to promote the formation of N-2 instead of being deeply hydrogenated into NH4+. Several activated carbon-supported Pt-In catalysts, activated under different calcination and reduction temperatures, have been also evaluated in nitrite reduction. The catalyst calcined and reduced at 400 degrees C showed the best performance considering both the activity and the selectivity to nitrogen. This enhanced selectivity is ascribed to the formation of Pt-In alloy. The electronic properties of Pt change upon alloy formation, as it is demonstrated by XPS.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 11