In the present study, potassium and caesium doped Ag/ catalysts were synthesized by simple wet impregnation method and evaluated for selective catalytic reduction (SCR) of NOx using methane. TEM analysis and diffraction patterns demonstrated the finely dispersed Ag particles. BET surface measurements reveal that the prepared materials have moderate to high surface area and the metal amount found from ICP analysis was well matching with the theoretical loadings. The synthesized K-Ag/ and Cs-Ag/ catalysts exhibited a promotional effect on deNOx activity in the presence of and . The long-term isothermal studies at under oxygen rich condition showed the superior catalytic properties of the both alkali promoted samples. The crucial catalytic properties of materials are attributed to NO adsorption properties detected by the NO TPD.

The influence of sulfate on the selective catalytic reduction of on the Ag/ catalyst was studied when was used as a reducing agent. Various preparation methods influenced differently on the activity. Among the methods, cogelation precipitation gave best activity. When sulfates were formed on the surfaces of samples prepared by impregnated and deposition precipitation, activity was enhanced as long as suitable forming condition is satisfied. The major sulfate formed in Ag/ catalyst was the aluminum sulfate and it seems that this sulfate acted as a promoter. When Mg was added to the Ag/ catalyst it promoted activity at high temperature. Intentionally added sulfate also enhanced activity, when their amount was confined less than 3 wt%.

The selective catalytic reduction(SCR) of nitric oxide by ethane in the presence of oxygen was investigated on Cu-ZSM-5, Co-ZSM-5 and Ga-ZSM-5 catalysts over a range of 400, 450 and 500℃. The catalysts were prepared by ion-exchange method. The composition of the reactant gases were 1000 ppm of NO, 1000 ppm of C2H6 and 2.5% of O2, and the reaction was conducted in a fixed-bed reactor at 1 atm. For the 20wt% Co-ZSM-5(50) catalyst, the NO conversion reached up to 100%, while the C2H6 conversion and the CO selectivity were about 50% and 25%, respectively, at 450℃. For the 20wt% Cu-ZSM-5(50) catalyst, the NO conversion and the C2H6 conversion were about 80% and 100%, respectively, but there was no CO produced. The metal ion-exchanged ZSM-5 catalysts exhibited a tendency to increase the NO conversion with the Si/Al ratio of the ZSM-5, that is, NO conversion was inversely proportional to the acidity of the catalysts. But, the effect of the acidity on NO conversion was not so large. From the XRD results of the catalysts before and after SCR reaction it was found that there was no structural change.

2016년부터 배출통제지역(ECA : Emission Control Atea)을 운항하는 선박에 대하여 배출되는 NOx(질소산화물) 및 SOx(황산화 물)의 배기량 감소규제가 강화되었다. 상기의 규제 물질 중 NOx를 제거하는 탈질장비 중 선택적 촉매 환원(SCR : Selectivity Catalytic Reduction) 시스템은 효율이 높고 상업적으로 많이 활용되고 있으나, 높은 온도에서 요소수가 활성화되는 단점이 있다. 이에 초미세기포를 이 용하여 낮은 온도에서도 반응할 수 있는 요소수 및 요소수 활성화 기기를 개발하여 상기의 문제점들을 최소화 할 수 있도록 하였다. 또한 SCR 시스템의 효율성을 향상시키는 방안을 마련하기 위하여, ANSYS-CFX package를 이용한 전산유체역학(CFD : Computational fluid dynamics)기법을 사용하였다. Navier-Stokes 방정식을 해석의 지배방정식으로 적용하여 SCR 시스템의 점성유동해석 시뮬레이션을 수행하였 다. SCR 시스템의 형상은 CATIA V5를 사용하여 3D 모델링을 하였고, SCR 시스템의 효율성을 비교하기 위해 요소수 분사 노즐의 위치를 요소수 분사 노즐은 배기관의 입구로부터 1/3, 1/2, 2/3로 변경하며 확인하였다. 또한, 노즐의 분사구 수가 SCR 시스템의 효율에 미치는 영향 을 확인하기 위하여 분사구 수가 4, 6, 8개일 경우를 시뮬레이션 하여 비교․분석하였다. 시뮬레이션 결과 배기관 입구에 가까울수록, 분사구 수가 많을수록 효율이 향상됨을 확인하였다.

A (5 wt.%)Mn-(1 wt.%)V2O5/TiO2 catalyst were prepared by co-precipitation method and used for low-temperature selective catalytic reduction (SCR) of NOx with ammonia in the presence of oxygen. The properties of the catalysts were studied by X-ray diffraction (XRD), temperature programmed reduction (TPR) and scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDS). The experimental results showed that (5 wt.%)Mn-(1 wt.%)V2O5/TiO2 catalyst yielded 81% NO conversion at temperature as low as 150℃ and a space velocity of 2,400 h-1. Crystalline phase of Mn2O3 was present at ≥15% Mn on V2O5/TiO2. XRD confirmed the presence of manganese oxide (Mn2O3) at 2θ=32.978°(222). The XRD patterns presented of (5 wt.%)Mn-(1 wt.%)V2O5/TiO2 did not show intense or sharp peaks for manganese oxides and vanadia oxides. The TPR profiles of (5 wt.%)Mn-(1 wt.%)V2O5/TiO2 catalyst showed main reduction peak of a maximum at 595℃.

V2O5/TiO2 catalysts promoted with Mn were prepared and tested for selective catalytic reduction of NOx in NH3. The effects of promoter content, degree of catalyst loading were investigated for NOx activity while changing temperatures, mole ratio, space velocity and O2 concentration. Among the various V2O5 catalysts having different metal loadings, V2O5(1 wt.%) catalyst showed the highest activity(98%) under wide temperature range of 200-250℃. When the V2O5 catalyst was further modified with 5 wt.% Mn as a promoter, the highest activity(90-47%) was obtained over the low temperature windows of 100-200℃. From Mn-V2O5/TiO2, it was found that by addition of 5 wt.% Mn on V2O5/TiO2 catalyst, reduction activity of catalyst was improved, which resulted in the increase of catalytic activity and NOx reduction. According to the results, NOx removal decreased for 10%, but the reaction temperature down to 100℃.