학술논문
Mechanistic investigation on Hg0capture over MnOxadsorbents: effects of the synthesis methods
Document Type
Article
Author
Source
Journal of Zhejiang University - Science A; January 2023, Vol. 24 Issue: 1 p80-90, 11p
Subject
Language
ISSN
1673565X; 18621775
Abstract
This study demonstrated the impacts of the synthesis methods on the textural structures, chemical properties, and Hg0capture capability of the MnOxsystem. Compared with the samples synthesized using the precipitation (PR) and hydrothermal (HT) methods, the adsorbent prepared via the sol-gel (SG) technique gave the best performance. At 150 °C, ca. 90% Hg0removal efficiency was reached after 7.5 h for MnOxprepared by the SG method, ca. 40% higher than that of the other two methods. The specific surface area of the adsorbent synthesized via the SG technique (23 m2/g) was almost double that of the adsorbent prepared by the HT method (12 m2/g) and three times that of the one prepared by the PR method (7 m2/g). The presence of plentiful acid sites from the SG method facilitated the physisorption of Hg0, making more Hg0available to be oxidized to HgO by the redox sites and thus giving the adsorbent prepared by the SG method the highest Hg0removal efficiency. The strong oxidative ability accelerated the oxidation of the physically adsorbed Hg0to HgO, which explained the higher Hg0removal efficiency of the sample prepared using the HT method than that of the one synthesized by the PR technique. During the whole Hg0removal cycles, chemisorption dominated, with the initial adsorption stage and the external mass-transfer process playing important roles.