Mechanochemical activation of titanium slag for effective selective catalytic reduction of nitric oxide

Hao Hou; Jizhi Zhou; Meiting Ji; Yang Yue; Guangren Qian; Jia Zhang

doi:10.1016/j.scitotenv.2020.140733

Mechanochemical activation of titanium slag for effective selective catalytic reduction of nitric oxide

Sci Total Environ. 2020 Nov 15:743:140733. doi: 10.1016/j.scitotenv.2020.140733. Epub 2020 Jul 7.

Authors

Hao Hou¹, Jizhi Zhou², Meiting Ji¹, Yang Yue³, Guangren Qian⁴, Jia Zhang⁵

Affiliations

¹ SHU Center of Green Urban Mining & Industry Ecology, School of Environmental and Chemical Engineering, Shanghai University, No. 381 Nanchen Road., Shanghai 200444, PR China.
² School of Economics, Shanghai University, No. 333 Nanchen Road., Shanghai 200444, PR China. Electronic address: jizhi.zhou@t.shu.edu.cn.
³ MGI of Shanghai University, Xiapu Town, Xiangdong District, Pingxiang City, Jiangxi 337022, PR China.
⁴ SHU Center of Green Urban Mining & Industry Ecology, School of Environmental and Chemical Engineering, Shanghai University, No. 381 Nanchen Road., Shanghai 200444, PR China; MGI of Shanghai University, Xiapu Town, Xiangdong District, Pingxiang City, Jiangxi 337022, PR China,. Electronic address: grqian@shu.edu.cn.
⁵ SHU Center of Green Urban Mining & Industry Ecology, School of Environmental and Chemical Engineering, Shanghai University, No. 381 Nanchen Road., Shanghai 200444, PR China; MGI of Shanghai University, Xiapu Town, Xiangdong District, Pingxiang City, Jiangxi 337022, PR China,. Electronic address: irujam@t.shu.edu.cn.

PMID: 32673916
DOI: 10.1016/j.scitotenv.2020.140733

Abstract

Ti-bearing blast furnace slag was usually recycled by acid leaching. For the first time, a catalyst was synthesized from the slag by wet ball-milling. During this process, no waste was produced. When the activated slag was used in selective catalytic reduction of nitric oxide (NO), 80.5 ± 1.2% of NO (990 ppm) was removed at 350 °C. The catalyst steadily removed 91.0 ± 1.3% of NO for 900 min at 400 °C. On the contrary, the slag without activation showed almost no catalytic activity at these temperatures. The enhanced activity was mainly attributed to the following characterizations. After wet ball-milling, specific surface area of the slag was increased from 2.595 to 26.497 m²/g; surface acid sites were amplified by 15 times; Fe/Ti ratio on surface was enhanced from 0.20 to 1.10. At the same time, surface Fe²⁺/Fe³⁺ was regulated from 0.43 to 0.53. The above enhanced properties were attributed to the mechanochemical activation, which dissolved and re-deposited active species on particle surface as well as reinforced the effect between Fe and Ti species. The main result of this work put forward a green method for the direct utilization of industrial waste without generating by-products.

Keywords: Mechanochemistry; Nitric oxide; Selective catalytic reduction; Slag.