In conclusion, metallic silver clusters contributed to the formation of nitrates and H2 dissociation, and the reduction of silver nitrates was the rate-determining step in the overall H2-NH3-SCR reaction.
결론적으로 금속성 은 클러스터는 질산염의 형성과 H2 해리에 기여했으며 질산은의 환원은 전체 H2-NH3-SCR 반응의 속도 결정 단계였다.
This review summarizes major advances in Cu-SSZ-13 applied to the NH3-SCR reaction, including the state of copper species, standard and fast SCR reaction mechanism, hydrothermal deactivation mechanism, poisoning resistance and synthetic methodology.
이 리뷰는 구리 종의 상태, 표준 및 고속 SCR 반응 메커니즘, 열수 비활성화 메커니즘, 내독성 및 합성 방법을 포함하여 NH3-SCR 반응에 적용된 Cu-SSZ-13의 주요 발전을 요약합니다.
As fast SCR reaction could accelerate the consumption of adsorbed NH3 species, it would benefit to restrain the competitive adsorption of SO2 and limit the reaction between adsorbed SO2 and NH3 species.
빠른 SCR 반응은 흡착된 NH3 종의 소비를 가속화할 수 있으므로 SO2의 경쟁적 흡착을 억제하고 흡착된 SO2와 NH3 종 사이의 반응을 제한하는 것이 좋습니다.
A model describing NH3 selective catalytic reduction (NH3-SCR) over Cu-ZSM-5 to investigate the effects of intraphase and interphase mass transfer on standard SCR reaction is developed and further verified with the synthetic gas bench.
Furthermore, in situ DRIFTS suggests a mixed Eley-Rideal (E-R) and Langmuir-Hinshelwood (L-H) mechanism for SCR reactions over this catalyst at low temperatures, where NH4NOx (x = 2 or 3) molecules are identified as key intermediates.
또한, 현장 DRIFTS는 NH4NOx(x=2 또는 3) 분자가 주요 중간체로 식별되는 저온에서 이 촉매에 대한 SCR 반응에 대한 혼합 Eley-Rideal(E-R) 및 Langmuir-Hinshelwood(L-H) 메커니즘을 제안합니다.
Since the presence of SO2 in feed gas had little effect on NH3 adsorption on the MnPrOx catalyst surface, and the inhibiting effect of SO2 on NO adsorption was alleviated, SCR reactions could still proceed in a near-normal way through the Eley-Rideal (E-R) mechanism on Pr-modified MnOx catalyst, while SCR reactions through the Langmuir-Hinshelwood (L-H) mechanism were suppressed slightly.
공급 가스 내 SO2의 존재는 MnPrOx 촉매 표면의 NH3 흡착에 거의 영향을 미치지 않았고 NO 흡착에 대한 SO2의 억제 효과가 완화되었기 때문에 SCR 반응은 여전히 Eley-Rideal(E-R)을 통해 거의 정상적인 방식으로 진행될 수 있었습니다. ) Pr-modified MnOx 촉매에 대한 메커니즘인 반면, Langmuir-Hinshelwood(L-H) 메커니즘을 통한 SCR 반응은 약간 억제되었습니다.
The catalytic performance of Cu/SAPO-34(TEAOH, TEA, MO) catalysts prepared with IWI and SSIE before and after exposure to water vapor at 70 °C was systemically examined, and their deactivation behavior during low-temperature NH3-SCR reaction was studied.
IWI 및 SSIE로 제조된 Cu/SAPO-34(TEAOH, TEA, MO) 촉매의 70 °C 수증기 노출 전후에 촉매 성능을 체계적으로 조사하였고, 저온 NH3-SCR 반응 시 비활성화 거동은 다음과 같다. 공부했다.
The particle-scale model segregates the SCR reactions from the parallel process of intracrystalline diffusion of reacting species using independently-estimated species diffusivities from diffusion-limited NH3 oxidation on a Pt/Al2O3@Na/ZSM-5.
입자 규모 모델은 Pt/Al2O3@Na/ZSM-5에 대한 확산 제한 NH3 산화로부터 독립적으로 추정된 종 확산도를 사용하여 반응 종의 결정내 확산의 병렬 프로세스에서 SCR 반응을 분리합니다.
The SCR performance and low temperature hydrothermal stability of Cu/SAPO-34 and CuCe/SAPO-34 before and after 70 ℃ hydrothermal aging were evaluated to conclude the impact of Ce on the structure stability and mechanism of NH3-SCR reaction.
70℃ 열수 노화 전후의 Cu/SAPO-34 및 CuCe/SAPO-34의 SCR 성능 및 저온 열수 안정성을 평가하여 NH3-SCR 반응의 구조 안정성 및 메커니즘에 대한 Ce의 영향을 결론지었다.
Based on H2 temperature-programmed reduction (H2-TPR) and electron paramagnetic resonance (EPR) results, Cu–O–Cu and isolated Cu species are suggested as main Cu species existing in Cu-IM-5 and are active for SCR reaction.
H2 온도 프로그램 환원(H2-TPR) 및 전자 상자성 공명(EPR) 결과를 기반으로 Cu-O-Cu 및 분리된 Cu 종은 Cu-IM-5에 존재하고 SCR 반응에 활성인 주요 Cu 종으로 제안됩니다.
The reaction mechanisms of the (Ce,La)CO3F and Mn/(Ce,La)CO3F catalysts were investigated by in-situ Fourier transform infrared spectroscopy (FTIR), to provide theoretical guidance for the specific reaction pathways of bastnaesite in the NH3-SCR reaction.
(Ce,La)CO3F 및 Mn/(Ce,La)CO3F 촉매의 반응 메커니즘은 NH3-에서 바스트네사이트의 특정 반응 경로에 대한 이론적 지침을 제공하기 위해 현장 푸리에 변환 적외선 분광법(FTIR)에 의해 조사되었습니다. SCR 반응.
It was also found that cerium species are more active in the low temperature NO-SCR reaction than tungsten ones (NO conversions obtained at 300 °C using CeO2–TiO2 and WO3–TiO2 were 75 and 0%, respectively).
A novel dual-function catalyst (CuW/CeO2–ZrO2) that can simultaneously catalyze NH3–SCR reaction and CO oxidation reaction, was synthesized by the co-impregnation method, aiming for simultaneous removal of NO and CO under oxygen-rich conditions.
Moreover, in situ DRIFTS was used to investigate the reaction mechanism, and the results indicate that the NH3-SCR reaction over MnCeOx/TiO2 and MnCeOx/TiO2-Al2O3 takes place by both the E–R and L–H mechanisms.
The dynamic NH3 adsorption has been investigated, shows that Ca doping content on catalyst is critical for SCR reaction, and the catalyst is more susceptible to SO2 initially in alkali flue gas during the actual application, but the sulfur resistance may increase with the alkali-poisoning effect aggravated by Ca doping.
Then, we will show how, among others, synchrotron-based X-ray spectroscopy, vibrational and optical spectroscopy (diffuse reflection infrared Fourier transform spectroscopy (DRIFTS) and diffuse reflection ultraviolet-visible spectroscopy (DRUVS)), electron paramagnetic spectroscopy (EPR), and impedance spectroscopy (IS) can be combined and complement each other to follow the evolution of coordinative environment and the local structure of Cu centers during low-temperature NH3-SCR reactions.
SDAs determined the formation of Cu/SAPO-34 catalyst, and the Cu/SAPO-34 catalyst adopting tetraethylenepentamine (TEPA) as SDA could maintain higher crystal integrity and active sites, which were in favor of the SCR reaction.
Among factors that determine the proximity, the effect of ion density on the SCR reaction is well established; however, it has not been verified how the different mobility of the Cu ion influences the SCR reaction.