The Role of Nitrate on the Sol-Gel Spread Self-Combustion Process and Its Effect on the NH<sub>3</sub>-SCR Activity of Magnetic Iron-Based Catalyst

Sol-gel spread self-combustion is the burning of the complexing agent in dried gel and the oxidant. Meanwhile, high temperature takes place during the combustion process, which is harmful to the pore structure of the catalyst. The nitrate from metal nitrate precursors as an oxidant could participate...

Full description

Bibliographic Details
Main Authors:	Xing Ning, Zhi-bo Xiong, Bin Yang, Wei Lu, Shui-mu Wu
Format:	Article
Language:	English
Published:	MDPI AG 2020-03-01
Series:	Catalysts
Subjects:	selective catalytic reduction of no<i><sub>x</sub></i> sol-gel the spread self-combustion method nitrate magnetic γ-fe<sub>2</sub>o<sub>3</sub>
Online Access:	https://www.mdpi.com/2073-4344/10/3/314

id	doaj-bb6d757650494c28ba8ca90324136e82
record_format	Article
spelling	doaj-bb6d757650494c28ba8ca90324136e822020-11-25T03:50:59ZengMDPI AGCatalysts2073-43442020-03-0110331410.3390/catal10030314catal10030314The Role of Nitrate on the Sol-Gel Spread Self-Combustion Process and Its Effect on the NH<sub>3</sub>-SCR Activity of Magnetic Iron-Based CatalystXing Ning0Zhi-bo Xiong1Bin Yang2Wei Lu3Shui-mu Wu4School of Energy and Power Engineering, University of Shanghai for Science & Technology, Jungong Road #516, Shanghai 200093, ChinaSchool of Energy and Power Engineering, University of Shanghai for Science & Technology, Jungong Road #516, Shanghai 200093, ChinaSchool of Energy and Power Engineering, University of Shanghai for Science & Technology, Jungong Road #516, Shanghai 200093, ChinaSchool of Energy and Power Engineering, University of Shanghai for Science & Technology, Jungong Road #516, Shanghai 200093, ChinaSchool of Energy and Power Engineering, University of Shanghai for Science & Technology, Jungong Road #516, Shanghai 200093, ChinaSol-gel spread self-combustion is the burning of the complexing agent in dried gel and the oxidant. Meanwhile, high temperature takes place during the combustion process, which is harmful to the pore structure of the catalyst. The nitrate from metal nitrate precursors as an oxidant could participate in the spread of the self-combustion process. Therefore, the influence of nitrate from metal nitrate on the spread self-combustion of an iron−cerium−tungsten citric acid gel and its catalytic performance of NO<i><sub>x</sub></i> reduction were investigated by removing nitrate via the dissolution of washing co-precipitation with citric acid and re-introducing nitric acid into the former solution. It was found that the removal of nitrate contributes to enhancing the NH<sub>3</sub>−SCR activity of the magnetic mixed oxide catalyst. The NO<i><sub>x</sub></i> reduction efficiency was close to 100% for Fe<sub>85</sub>Ce<sub>10</sub>W<sub>5</sub>−CP−CA at 250 °C while the highest was only 80% for the others. The results of thermal analysis demonstrate that the spread self-combustion process of citric acid dried gel is enhanced by re-introducing nitric acid into the citric acid dissolved solution when compared with the removal of nitrate. In addition, the removal of nitrate helps in the formation of γ-Fe<sub>2</sub>O<sub>3</sub> crystallite in the catalyst, refining the particle size of the catalyst and increasing its pore volume. The removal of nitrate also contributes to the formation of Lewis acid sites and Brønsted acid sites on the surface of the catalyst compared with the re-introduction of nitric acid. The in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) demonstrates that both Eley−Rideal (E−R) and Langmuir−Hinshelwood (L−H) mechanisms exist over Fe<sub>85</sub>Ce<sub>10</sub>W<sub>5</sub>−CP−CA at 250 °C with E−R as its main mechanism.https://www.mdpi.com/2073-4344/10/3/314selective catalytic reduction of no<i><sub>x</sub></i>sol-gelthe spread self-combustion methodnitratemagnetic γ-fe<sub>2</sub>o<sub>3</sub>
collection	DOAJ
language	English
format	Article
sources	DOAJ
author	Xing Ning Zhi-bo Xiong Bin Yang Wei Lu Shui-mu Wu
spellingShingle	Xing Ning Zhi-bo Xiong Bin Yang Wei Lu Shui-mu Wu The Role of Nitrate on the Sol-Gel Spread Self-Combustion Process and Its Effect on the NH<sub>3</sub>-SCR Activity of Magnetic Iron-Based Catalyst Catalysts selective catalytic reduction of no<i><sub>x</sub></i> sol-gel the spread self-combustion method nitrate magnetic γ-fe<sub>2</sub>o<sub>3</sub>
author_facet	Xing Ning Zhi-bo Xiong Bin Yang Wei Lu Shui-mu Wu
author_sort	Xing Ning
title	The Role of Nitrate on the Sol-Gel Spread Self-Combustion Process and Its Effect on the NH<sub>3</sub>-SCR Activity of Magnetic Iron-Based Catalyst
title_short	The Role of Nitrate on the Sol-Gel Spread Self-Combustion Process and Its Effect on the NH<sub>3</sub>-SCR Activity of Magnetic Iron-Based Catalyst
title_full	The Role of Nitrate on the Sol-Gel Spread Self-Combustion Process and Its Effect on the NH<sub>3</sub>-SCR Activity of Magnetic Iron-Based Catalyst
title_fullStr	The Role of Nitrate on the Sol-Gel Spread Self-Combustion Process and Its Effect on the NH<sub>3</sub>-SCR Activity of Magnetic Iron-Based Catalyst
title_full_unstemmed	The Role of Nitrate on the Sol-Gel Spread Self-Combustion Process and Its Effect on the NH<sub>3</sub>-SCR Activity of Magnetic Iron-Based Catalyst
title_sort	role of nitrate on the sol-gel spread self-combustion process and its effect on the nh<sub>3</sub>-scr activity of magnetic iron-based catalyst
publisher	MDPI AG
series	Catalysts
issn	2073-4344
publishDate	2020-03-01
description	Sol-gel spread self-combustion is the burning of the complexing agent in dried gel and the oxidant. Meanwhile, high temperature takes place during the combustion process, which is harmful to the pore structure of the catalyst. The nitrate from metal nitrate precursors as an oxidant could participate in the spread of the self-combustion process. Therefore, the influence of nitrate from metal nitrate on the spread self-combustion of an iron−cerium−tungsten citric acid gel and its catalytic performance of NO<i><sub>x</sub></i> reduction were investigated by removing nitrate via the dissolution of washing co-precipitation with citric acid and re-introducing nitric acid into the former solution. It was found that the removal of nitrate contributes to enhancing the NH<sub>3</sub>−SCR activity of the magnetic mixed oxide catalyst. The NO<i><sub>x</sub></i> reduction efficiency was close to 100% for Fe<sub>85</sub>Ce<sub>10</sub>W<sub>5</sub>−CP−CA at 250 °C while the highest was only 80% for the others. The results of thermal analysis demonstrate that the spread self-combustion process of citric acid dried gel is enhanced by re-introducing nitric acid into the citric acid dissolved solution when compared with the removal of nitrate. In addition, the removal of nitrate helps in the formation of γ-Fe<sub>2</sub>O<sub>3</sub> crystallite in the catalyst, refining the particle size of the catalyst and increasing its pore volume. The removal of nitrate also contributes to the formation of Lewis acid sites and Brønsted acid sites on the surface of the catalyst compared with the re-introduction of nitric acid. The in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) demonstrates that both Eley−Rideal (E−R) and Langmuir−Hinshelwood (L−H) mechanisms exist over Fe<sub>85</sub>Ce<sub>10</sub>W<sub>5</sub>−CP−CA at 250 °C with E−R as its main mechanism.
topic	selective catalytic reduction of no<i><sub>x</sub></i> sol-gel the spread self-combustion method nitrate magnetic γ-fe<sub>2</sub>o<sub>3</sub>
url	https://www.mdpi.com/2073-4344/10/3/314
work_keys_str_mv	AT xingning theroleofnitrateonthesolgelspreadselfcombustionprocessanditseffectonthenhsub3subscractivityofmagneticironbasedcatalyst AT zhiboxiong theroleofnitrateonthesolgelspreadselfcombustionprocessanditseffectonthenhsub3subscractivityofmagneticironbasedcatalyst AT binyang theroleofnitrateonthesolgelspreadselfcombustionprocessanditseffectonthenhsub3subscractivityofmagneticironbasedcatalyst AT weilu theroleofnitrateonthesolgelspreadselfcombustionprocessanditseffectonthenhsub3subscractivityofmagneticironbasedcatalyst AT shuimuwu theroleofnitrateonthesolgelspreadselfcombustionprocessanditseffectonthenhsub3subscractivityofmagneticironbasedcatalyst AT xingning roleofnitrateonthesolgelspreadselfcombustionprocessanditseffectonthenhsub3subscractivityofmagneticironbasedcatalyst AT zhiboxiong roleofnitrateonthesolgelspreadselfcombustionprocessanditseffectonthenhsub3subscractivityofmagneticironbasedcatalyst AT binyang roleofnitrateonthesolgelspreadselfcombustionprocessanditseffectonthenhsub3subscractivityofmagneticironbasedcatalyst AT weilu roleofnitrateonthesolgelspreadselfcombustionprocessanditseffectonthenhsub3subscractivityofmagneticironbasedcatalyst AT shuimuwu roleofnitrateonthesolgelspreadselfcombustionprocessanditseffectonthenhsub3subscractivityofmagneticironbasedcatalyst
_version_	1724489424963633152

The Role of Nitrate on the Sol-Gel Spread Self-Combustion Process and Its Effect on the NH<sub>3</sub>-SCR Activity of Magnetic Iron-Based Catalyst

Similar Items