Exploring the activity of chemical-activated carbons synthesized from peach stones as metal-free catalysts for wet peroxide oxidation

• Type: Article in International Scientific Journal
• Date: 2018

Authors

Adrián M. T. Silva (Author) FEUP; Maria Martin-Martinez (Author) Other; Silvia Álvarez-Torrellas (Author) Other; Juan García (Author) Other; Joaquim L. Faria (Author) FEUP; Helder T. Gomes (Author) Other

Journal

Title: Catalysis Today

Vol. 313 No. SI

Pages: 20-25

ISSN: 0920-5861

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 0 Citations

ISI Web of Science

Scopus - 7 Citations

Scientific classification

CORDIS: Technological sciences

Associated Projects

AIProcMat@N2020 - Advanced Industrial Processes and Materials for a Sustainable North Region of Portugal2020

Other information

Authenticus ID: P-00P-038

DOI: 10.1016/j.cattod.2018.01.003

Abstract (EN): Peach stones were used as raw material for the synthesis of activated carbons with different properties. Firstly, peach stones were chemically activated using a 12M H3PO4 solution and carbonized under flowing air (400 degrees C). The obtained activated carbon, named as PS, is characterized by a high surface development (SBET=1262m(2) g(-1)) and acidic character (pH(PZC)=4.2). A fraction of PS was further carbonized under N-2 atmosphere at 800 degrees C to remove surface functionalities and to increase its basicity (PS-800). In addition, a Pt catalyst supported on PS (3% w/w Pt/PS) was synthesized by incipient wetness impregnation, resulting in a considerable hydrophilicity increasing. The synthesized materials were tested in the catalytic wet peroxide oxidation (CWPO) of highly concentrated solutions of 4-nitrophenol (4-NP, 5 gL(-1)) during 24 h experiments, conducted at relatively mild operating conditions (T= 50-110 degrees C, pH=3, catalyst load=2.5 gL(-1) and [H2O2](0)=17.8 gL(-1), corresponding to the stoichiometric amount of H2O2 needed for the complete mineralization of 4-NP). It was observed that the increase of electron-donating functionalities in PS-800 promotes the generation of reactive HO% radicals, being the activity towards CWPO twice higher than that obtained with the pristine PS. Besides, increasing operating temperature substantially enhances CWPO, finding a 80% of 4-NP removal at 110 degrees C. On the other hand, despite the sharp increment in H2O2 decomposition due to the presence of Pt particles in Pt/PS catalyst, this decomposition is inefficient in all cases, with a consequent poor pollutant removal. This can be attributed to the recombination of HO% radicals into non-reactive species - scavenging effects, promoted by the hydrophilicity of the catalyst.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 6