Preparation Of TiO₂ Nanotubes And Its Application In NH₃-SCR Denitration Catalyst

Nitrogen oxides (NOx) have done great harm to humans and nature, it has bad effects on human health and leads to a series of environmental problems such as acid rain,photochemical smog and the destruction of the ozone layer and so on. Selective catalytic reduction (SCR) is considered one of the most effective denitrification technology and its core is the catalyst. In recent years, low-temperature SCR denitration catalyst has not met requirement. TiO2 nanotube with great surface area and strong adsorption capacity has now been applied to solar photocatalysis and other fields but it's application in SCR denitration catalyst is very few.In this paper, TiO2 nanotubes were synthesized by hydrothermal method, and the effects of surfactant type, hydrothermal reaction temperature and time, and concentration of added surfactant on nanotube's composition and morphology was investigated. The study finds adding CTAB in hydrothermal reaction for the preparation of TiO2 nanotubes is very favorable; the hydrothermal reaction temperature is not better too high (130? is enough);nanotubes have reached the best morphology when reaction time is 24h, and there is no significant improvement in morphology and crystal form as time going on; we also find a greater effect of different concentrations of CTAB added to the hydrothermal reaction on the nanobubes-by adjusting the concentration of CTAB, we basically synthesized controllable nanotubes.Using the TiO2 nanotubes in good morphology as the carrier, we prepared Mn-Fe/TiNT,Mn-Ce/TiNT, Mn-Ce-Fe/TiNT catalysts, and as contrasts, Mn-Fe/TiO2, Mn-Ce/TiO2,Mn-Ce-Fe/TiO2 catalysts with the same active ingredient and using nano-TiO2 powder as a carrier were composed,after that, low temperature denitration activity of these catalysts were tested. We found that the carrier had great effects on the activity of catalyst: the low-temperature denitrification activity of TiO2 nanotube-supported catalysts were significantly stronger than catalysts using nano-TiO2 powder as carrier; and wherein the catalysts, Mn-Ce/TiNT and Mn-Ce-Fe/TiNT's denitration activity were the best: between 100?-200? their activity were all more than 90%.