Size effect of Pt nanoparticles in acid-assisted soot oxidation in the presence of NO

Shuting Luo; Xiaodong Wu; Baofang Jin; Shuang Liu; Rui Ran; Zhichun Si; Duan Weng

doi:10.1016/j.jes.2020.04.008

Size effect of Pt nanoparticles in acid-assisted soot oxidation in the presence of NO

J Environ Sci (China). 2020 Aug:94:64-71. doi: 10.1016/j.jes.2020.04.008. Epub 2020 Apr 17.

Authors

Shuting Luo¹, Xiaodong Wu², Baofang Jin¹, Shuang Liu³, Rui Ran¹, Zhichun Si⁴, Duan Weng⁵

Affiliations

¹ Key Laboratory of Advanced Materials of Ministry of Education, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China.
² Key Laboratory of Advanced Materials of Ministry of Education, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China. Electronic address: wuxiaodong@tsinghua.edu.cn.
³ School of Materials Science and Engineering, Ocean University of China, Qingdao 266100, China.
⁴ Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China.
⁵ Key Laboratory of Advanced Materials of Ministry of Education, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China; Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China.

PMID: 32563488
DOI: 10.1016/j.jes.2020.04.008

Abstract

Pt/Al₂O₃ catalysts with mean Pt particle size ranged from 2.7 to 7.1 nm were synthesized by chemical reduction method, and the sulfated counterparts were prepared by impregnation of sulfuric acid. The turnover frequency of platinum for soot oxidation under loose contact conditions in a feed flow containing NO and O₂ are positively correlated with the size of platinum. The sulfated Pt/Al₂O₃ exhibits higher catalytic activity for soot oxidation in the presence of NO despite their reduced ability for NO₂ production. Such a contradiction is more significant for those catalysts with smaller platinum particles. Herein, the catalysts were characterized by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), transmission electron microscopy (TEM), inductive coupled plasma (ICP) emission spectrometry, CO chemisorption, thermogravimetric analysis (TGA), NH₃ temperature-programmed desorption (NH₃-TPD), NO temperature-programmed oxidation (TPO) and NO_x temperature-programmed desorption (TPD). Possible effect of Pt particle size for the catalytic oxidation of soot in the presence of NO was presented based primarily on the promoted NO₂ transfer efficiency onto the soot pushed by the acidic catalysts.

Keywords: NO(2) transfer; Particle size effect; Pt/Al(2)O(3); Soot oxidation; Sulfation.

MeSH terms

Catalysis
Nanoparticles*
Oxidation-Reduction
Soot*
X-Ray Diffraction

Substances

Soot