Liu Qinglong,Yang Jingchao,Luo Mingsheng,Yang Zhi,Zhao Qiuna
Abstract A series of Mn–Ti oxide catalysts were synthesized by the sol–gel method and the effects of different synthesis conditions were investigated in sequence. The microstructures and properties of the catalysts were characterized by using N 2 adsorption–desorption, XRD, SEM, H 2 -TPR, NH 3 -TPD, Raman and XPS. The catalytic performance over Mn–Ti oxide catalysts prepared under different synthesis conditions for the low-temperature SCR of NO with NH 3 were also comparatively evaluated. The results reveal that the calcination temperature and metal source play a significant role in the characteristics and the SCR activities of the catalysts. A relatively low calcination temperature is beneficial to low-temperature SCR activity. Manganese nitrate or manganese acetate as the Mn source combining with tetrabutyl titanate as Ti source can achieve high SCR activities. The excellent low-temperature NH 3 -SCR activity can be ascribed to the appropriate textural properties, amorphous Mn-oxides with equal ratio of Mn 3+ /Mn 4+ , good low-temperature reducibility and abundant surface B-acid sites. Graphic Abstract
Chengxin Li,Zhuwei Gao,Xinyu Qi,Xintong Han,Zhongxin Liu
To control the water pollution caused by industrial oily wastewater, scientific research in the field of oil-water separation has begun all over the world, which has also attracted extensive attention to green advanced separation materials. Herein, we used stainless steel mesh as one of the reactants to load metal oxide particles formed by tetrabutyl titanate (TBT), and manganese acetate on cotton mesh under acidic conditions to prepare a membrane material with excellent oil-water separation. The results showed that the 0.1/0.3/0.5 Mn-TiO2/Fe membranes prepared by high-temperature hydrothermal reaction had an excellent separation effect in the light oil and water separation after 10 cycles, and its maximum oil-water separation efficiency was 89.87%, 92.65% and 96.96% respectively. At the same time, the membrane still had good hydrophobicity after acid, alkali and high temperature and low-temperature treatment. In the light oil and water separation experiment measured after 15 times of friction with sandpaper, the 0.5Mn-TiO2/Fe membrane showed good durability, and the average separation efficiency was 93.82% respectively. This diversified wettability and separation process of stainless steel mesh load on the membrane surface has a wide range of potential applications in environmental protection, energy utilization, industrial manufacturing and so on.