Cu–Ni/AC Catalyst for Low-Temperature CO-Selective Catalytic Denitration Mechanism

Abstract

To study the preparation principle of Cu−Ni/AC catalysts and the mechanism of low-temperature CO-selective catalytic reduction (SCR) denitration, Cu−Ni/AC catalysts with different metal loadings were prepared by the isometric ultrasonic impregnation method. It was determined that the 10Cu−4Ni/AC catalyst had the best CO-SCR low-temperature denitration rate of 94.2% in 5% O 2 and at the denitration temperature of 150 °C. The characterization of Cu−Ni/AC by scanning electron microscopy (SEM), Brunauer−Emmett−Teller (BET), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and CO temperature-programmed desorption (TPD) confirmed that the copper−nickel-coordinated loading resulted in the Cu−Ni/AC catalyst having a rich pore structure and a large number of acidic oxygen-containing functional groups. The spherical particles of copper−nickel oxide with good thermal stability were highly dispersed on the AC surface, allowing the copper and nickel metal ions to enter the graphite or graphite-like microcrystalline structure and split into smaller irregular graphene fragments, thus forming a large number of denitration reaction units on the AC surface. The oxidation−reduction reaction (Cu 2+ + Ni 2+ → Cu + + Ni 3+ ) between copper and nickel metal oxides produced active oxygen vacancies, which increased the amount of oxygen (Oa) adsorbed on the surface, especially acidic adsorption sites on the surface; this promoted the higher adsorption of reaction gases (CO, O 2 , NO), leading to the conversion of a standard SCR reaction to a fast SCR reaction, which, in turn, improved the denitration efficiency. The CO-SCR denitrification mechanism model of the Cu−Ni/AC catalyst was discovered and established according to the experimental results and theoretical analysis. The related research provides a reference for carbon-based catalysts for low-temperature CO-SCR denitration.

Acidified SiO2 Supported Fe-based Bimetal Oxide Catalyst with Resistance to High-Level Alkali Poisoning for CO Selective Catalytic Reduction of NO Removal of NOx

“…Nitrogen oxides (NO x ), as the primary atmospheric pollutants produced by the combustion of carbon-based fuels, have posed risks to both ecology and human health, such as ozone depletion, greenhouse effect, and lung diseases. − With increasingly stringent standards on NO x emissions, nitrogen removal technologies have attracted tremendous attention in recent years. Wherein selective catalytic reduction of NO x by CO (CO-SCR) shows immense potential, especially in applications with notable CO generation, including power plant boilers, vehicle exhaust, and activated carbon regeneration gas. , It can avoid the drawbacks of the industrial NH 3 -SCR process (e.g., ammonia escape, toxicity, and equipment corrosion), as well as facilitating simultaneous removal of multiple pollutants. , Recently, cost-effective transition metal-based catalysts have drawn widespread research interest for CO-SCR with superb activities competitive to noble metal contained materials. , …”

Efficient Catalysis for Low-Temperature CO Selective Catalytic Reduction over an Fe-Cu Bimetal Oxide Catalyst Supported on Amorphous SiO2

“…To address these issues, scholars have conducted research on the effect of the catalyst support. , Some prominent results have been obtained in the research on TiO 2 , Al 2 O 3 , SiO 2 , molecular sieves, and carbon-based materials, but the applications of these supported catalysts have been limited by the high cost, recycling, and hydrothermal stability problems. , It is worth noting that activated carbon, such as rice husk char, has a strong adsorption capacity and deoxidizing ability to promote the reaction between CO and NOx . Additionally, the abundant inner surface and uniform pore size of SiO 2 mesoporous materials make them be used widely in catalysis, catalytic supports, and molecular adsorption.…”

CO + NH3 coupling denitration at low temperatures over manganese/activated carbon catalysts

“…Studies have shown that active metal components can be loaded into AC to improve its low-temperature denitration activities. The metals used as active components are mainly iron (Fe), 9 manganese (Mn), 10 copper (Cu), 6 cobalt (Co), 11 cerium (Ce), 10,11 platinum (Pt), 12 palladium (Pd), 13 rhodium (Rh), 14 and silver (Ag), 14,15 of which Mn has good low-temperature denitration activity. 16 In the field of NH 3 -SCR denitration, J. Y. Chen et al 17 found that MnO x loaded into Fe 2 O 3 /AC increases amorphous dispersion, the Fe 3+ /(Fe 3+ + Fe 2+ ) and Mn 4+ /Mn 3+ ratio, specific surface area, and pore volume.…”

“…4 Carbon monoxide (CO) and ammonia (NH 3 ) are reducing agents for SCR. One technical advantage of CO-SCR 5,6 is that CO exists in automobile exhaust and industrial exhaust gases. Using it as a reducing agent to treat NO x treats waste with waste; however, this method has challenges.…”