Characteristics of Manganese Supported on Hydrous Titanium Oxide Catalysts for the Selective Catalytic Reduction of NOx with Ammonia

Abstract

Mn oxide supported on two different groups of titania, hydrous or crystalline titanium oxide, were investigated for the selective catalytic reduction of NO x with NH 3 (NH 3 SCR). Hydrous titania was prepared by hydrolysis of titanium tetraisopropoxide followed by drying, and crystalline titanium oxide was prepared with further calcination of the hydrous titania. Mn supported on hydrous TiO 2 catalyst exhibited higher NO x conversion over wide temperature range (150-400°C) as well as the suppressed formation of nitrous oxide compared to Mn supported on crystalline TiO 2 . Also, Mn/hydrous TiO 2 showed relatively lower performance in ammonia oxidation than Mn/crystalline TiO 2 which is regarded as the side reaction. Several combined characterization results indicate that manganese species more strongly interact with hydrous TiO 2 than crystalline TiO 2 , resulting in different redox behavior and oxidation state of Mn oxides. It can be concluded that the activity and selectivity of Mn/TiO 2 catalysts in NH 3 SCR reaction were affected by initial state of titania support.

Rotation-Assisted Hydrothermal Synthesis of Thermally Stable Multiwalled Titanate Nanotubes and Their Application to Selective Catalytic Reduction of NO with NH3

“…Vanadium–tungsten oxide dispersed on a titanium-oxide catalyst is a conventional catalyst for the SCR of NO x , one of the major air pollutants, using NH 3 as a reducing agent. − Many researchers have tried to find metal oxide structures with improved properties for SCR applications. − …”

Chemisorption of NH3 on Monomeric Vanadium Oxide Supported on Anatase TiO2: A Combined DRIFT and DFT Study

“…Commercial TiO 2 (P25, Degussa) powder was used in this work. VO x /TiO 2 samples were prepared with the conventional wet impregnation method . Ammonium metavanadate (99%, Sigma Aldrich) with the amount of targeted V surface concentration was dissolved in 0.05 M oxalic acid solution to make the vanadium precursor solution.…”

“…VO x /TiO 2 samples were prepared with the conventional wet impregnation method. 41 Ammonium metavanadate (99%, Sigma Aldrich) with the amount of targeted V surface concentration was dissolved in 0.05 M oxalic acid solution to make the vanadium precursor solution. The mixture of TiO 2 powder and the vanadium precursor solution was stirred for 30 min and subsequently vaporized in a rotary evaporator.…”

A Study on the Effect of Different Ball Milling Methods on the NH3-SCR Activity of Aluminum-Laden Bayan Obo Tailings

“…After magnetic separation and REE flotation, the tailings still contain a large number of valuable minerals such as iron, niobium and rare earth elements which are not effectively utilized, causing serious waste of resources. The question of how to efficiently use Bayan Obo rare-earth tailings has always been the research focus of domestic scholars [1][2][3]. In view of today's serious air pollution, using precious metals as the active ingredient to prepare catalysts is not only expensive, but also may cause sulfur poisoning.…”