10,694 Results Found

Current developments in exhaust gas aftertreatment led to a huge mistrust in diesel driven passenger cars due to their NO_x emissions being too high. The selective catalytic reduction (SCR) with ammonia (NH₃) as reducing agent is the only approach tod...

The present work is focused on the effect of water on NH₃ adsorption over Cu-CHA SCR catalysts. For this purpose, samples characterized by different SAR (SiO₂/Al₂O₃) ratios and Cu loadings were studied under both dry and wet conditions. H₂O adversely...

Typically, to meet emission regulations, the selective catalytic reduction of NO_X with NH₃ (NH₃-SCR) technology cause NH₃ emissions owing to high NH₃/NO_X ratios to meet emission regulations. In this study, V-Cu/BN-Ti was used to remove residual NO_X a...

A unified transient kinetic model which can predict the adsorption, desorption and oxidation kinetics of NH₃ over hydrothermally aged Cu-chabazite was developed. The model takes into account the variation of fractional coverages of NH₃ storage sites...

This study proposed the integrated design of an NH₃ fuel supply system and a re-liquefaction system for an ocean-going NH₃-fueled ship. The target ship was a 14,000 TEU large container ship traveling from Asia to Europe. The NH₃ fuel supply system wa...

Recently, the design and fabrication of lead (Pb)-free perovskite or perovskite-like materials have received great interest for the development of perovskite solar cells (PSCs). Manganese (Mn) is a less toxic element, which may be an alternative to P...

Aging diesel engines on the road require the development of an after-treatment system to meet current emission regulations, and a reduction in NOx (Nitrogen Oxide) is significant. The SCR (Selective Catalytic Reduction) system is the after-treatment...

Two-dimensional (2D) ferroelectrics usually exhibit instability or a tendency toward degradation when exposed to the ambient atmosphere, and the mechanism behind this phenomenon remains unclear. To unravel this affection mechanism, we have undertaken...

Nanosized SSZ-13 was synthesized hydrothermally by applying N,N,N-trimethyl-1-adamantammonium hydroxide (TMAdaOH) as a structure-directing agent. In the next step, the quantity of TMAdaOH in the initial synthesis mixture of SSZ-13 was reduced by half...

The NH₃ sensor is of great significance in preventing NH₃ leakage and ensuring life safety. In this work, the Pd-decorated ZnO hexagonal microdiscs are synthesized using hydrothermal and annealing processes, and the gas sensor is fabricated based on...

This study centers on the development and characterization of an innovative electrochemical sensing probe composed of a sensing mesoporous functional sol–gel coating integrated onto a glassy carbon electrode (sol–gel/GCE) for the detectio...

The reaction of NH₂ radicals with C₃H₈ is crucial for understanding the combustion behavior of NH₃/C₃H₈ blends. In this study, we investigated the temperature dependence of the rate coefficients for the hydrogen abstraction reactions of C₃H₈ by NH₂ r...

Due to high greenhouse gas emissions, countries worldwide are stepping up their emission reduction efforts, and the global demand for new, carbon-free fuels is growing. Ammonia (NH₃) fuels are popular due to their high production volume, high energy...

Support effect is an important issue in heterogeneous catalysis, while the explicit role of a catalytic support is often unclear for catalytic reactions. A systematic density functional theory computational study is reported in this paper to elucidat...

[NH₃(CH₂)₅NH₃]MnCl₄ crystals are grown via slow evaporation, and the crystal undergoes a phase transition at 298 K (T_C) according to differential scanning calorimetry, and the structures determined via X-ray diffraction at 173 and 333 K are orthorhom...

The hydrogen flux inhibition of Pd-Ru membranes under exposure to 1–10% NH₃ at 673–773 K was investigated. The Pd-Ru membranes were characterized by XRD, SEM, XPS, and hydrogen permeation tests. The results show that when exposed to 1&nda...

Proton transport is an elementary process in the selective catalytic reduction of nitrogen oxides by ammonia (DeNO_x by NH₃-SCR) using metal-exchanged zeolites as catalysts. This review summarizes recent advancements in the study of proton transport i...

Spherical MCM-41 with various copper and iron loadings was prepared by surfactant directed co-condensation method. The obtained samples were characterized with respect to their structure (X-ray diffraction, XRD), texture (N₂ sorption), morphology (sc...

LaMnO₃ with perovskite structure is a SCR de-NO_x catalyst with good performance at low temperatures. In this paper, the SCR reaction process on the 010 surface of LaMnO₃ catalyst was studied by DFT method, to guide the development of catalysts and th...

The development of new options to reduce ammonia (NH₃) emissions during slurry manure storage is still required due to the shortcomings of the current technologies. This study aimed to identify to what extent untreated and acid-treated biochar (BC) a...

H₃PW₁₂O₄₀-modified MnO_x catalysts (denoted as Mn-HPW) were used for NO_x elimination with co-fed NH₃. The optimal Mn-HPW_0.02 catalyst exhibited over 90% NO_x conversion at 90–270 °C. The incorporation of HPW increased the amount of Lewis acid...

FeVO₄ and Fe_0.5Er_0.5VO₄ were prepared and loaded over standard Selective Catalytic Reduction (SCR) supports based on TiO₂-WO₃-SiO₂ (TWS) and redox active supports like CeO₂ and CeZrO₂ with the aim of finding a suitable formulation for simultaneous so...

Ammonia (NH₃) is a crucial alkaline component in the atmosphere, with significant impacts on environmental and ecosystem health. However, our understanding of the long-term variability characteristics of NH₃ emissions is still limited due to the scar...

Sb-containing catalysts (SbZrO_x (SbZr), SbCeO_x (SbCe), SbCeZrO_x (SbCeZr)) were prepared by citric acid method and investigated for the selective catalytic reduction (SCR) of NO_x with NH₃ (NH₃-SCR). SbCeZr outperformed SbZr and SbCe and exhibited the...

The effect of Mn impregnation on the NH₃-SCR (selective catalytic reduction of NO_x by NH₃) activity of in situ synthesized Cu-SSZ-13 was investigated in this work. It was found that Mn addition could efficiently improve the low-temperature activity o...

CeNbTi catalyst was poisoned in different sulfur poisoning atmospheres at 300 °C for 6 h and then was evaluated for selective catalytic reduction (SCR) of NO_x with NH₃. The catalyst deactivation upon SO₂ exposure was effectively inhibited in the...

Copper and iron promoted ZrO₂ catalysts were prepared by one-pot synthesis using urea. The studied catalysts were characterized by XRD, N₂ physisorption, XPS, NH₃-TPD, and tested in the selective catalytic reduction of NO with NH₃ (NH₃-SCR) in the ab...

A systematic modeling approach was scrutinized to develop a kinetic model and a novel monolith channel geometry was designed for NH₃ selective catalytic reduction (NH₃-SCR) over Cu-ZSM-5. The redox characteristic of Cu-based catalysts and the variati...

Coal is a major contributor to the global emission of nitrogen oxides (NO_x). The NO_x formation during coal utilization typically derives from the thermal decomposition of N-containing compounds (e.g., pyrrolic groups). NH₃ and HCN are common precurso...

Nitrogen oxides (NO_x), one of the major air pollutants, not only are key substances in forming acid rain and photochemical smog, but can also enter the stratosphere and damage the ozone layer to some extent. The selective catalytic reduction (NH₃-SCR...

The NH₃-SCR activities and hydrothermal stabilities of five xCu/MCM-22 zeolites with different Cu loadings (x = 2–10 wt%) prepared by incipient wetness impregnation method were systematically investigated. The physicochemical properties of xCu/...

Ammonia-based selective catalytic reduction is one of the most effective NO_x reduction technologies for diesel engines, but its low NO_x reduction efficiency under low-temperature conditions needs further improvement. Previous studies have broadened o...

The upcoming more stringent automotive emission legislations and current developments have promoted new technologies for more precise and reliable catalyst control. For this purpose, radio-frequency-based (RF) catalyst state determination offers the...

Both NH₃ and H₂ are considered to be carbon-free fuels, and their mixed combustion has excellent performance. Considering the laminar burning velocity as a key characteristic of fuels, accurately predicting the laminar burning velocity of NH₃/H₂/Air...

Platinum’s (Pt) poisoning effect on Cu-SSZ-13 and its regeneration were investigated. The Pt enhanced the parallel reactions, such as NH₃ oxidation and NO oxidation reactions, which decreased the deNOx activities. In the temperature range below 330 °...

Photovoltaic (PV) cells based on single-walled carbon nanotube (SWCNT)/silicon (Si) and multiwalled carbon nanotube (MWCNT)/Si junctions were tested under exposure to NH₃ in the 0–21 ppm concentration range. The PV cell parameters remarkably ch...

A layered Ti₃C₂T_x MXene structure was prepared by etching MAX-phase Ti₃AlC₂ with hydro-fluoric acid (HF), followed by alkalization in sodium hydroxide (NaOH) solutions of varying concentrations and for varying durations. Compared to sensors utilizing...

To reveal the role of SO₃ poisoning in Cu/SSZ-13 NH₃-SCR catalysts, fresh and sulfated Cu/SSZ-13 catalysts were prepared in the presence or absence of SO₃ flux. The deactivation mechanism is probed by the changes of structural, copper species, and se...

Promotion of 2.73% Fe₂O₃ in an in-house-made V₂O₅-WO₃/TiO₂ (VWT) and a commercial V₂O₅-WO₃/TiO₂ (c-VWT) has been investigated as a cost effective approach to the suppression of N₂O formation in the selective catalytic reduction of NO by NH₃ (NH₃-SCR)...

The objective of the study is to present the modeling and multi-objective optimization of NO_x conversion efficiency and NH₃ slip in the Selective Catalytic Reduction (SCR) catalytic converter for a diesel engine. A novel ensemble method based on a su...

The thermochemical energy-storage material couple CuSO₄/[Cu(NH₃)₄]SO₄ combines full reversibility, application in a medium temperature interval (<350 °C), and fast liberation of stored heat. During reaction with ammonia, a large change in the...

Nitrogen oxides (NO_x), harmful pollutants primarily from fossil fuel combustion, pose significant environmental and health risks. Among mitigation technologies, NH₃-SCR is widely adopted due to its high efficiency and industrial viability. MnO₂-based...

Cu-containing CHA type (Cu-CHA) zeolites have been widely investigated owing to their excellent low-temperature activity and high hydrothermal stability in selective catalytic reduction of NO_x with NH₃ (NH₃-SCR). Herein, a series of Cu-SAPO-44 zeolit...

Ammonia (NH₃) is a promising carbon-free fuel for internal combustion engines, but its low reactivity and poor ignition properties present significant challenges for stable operation. This study presents the development and experimental validation of...

SAPO-34 was prepared with a mixture of three templates containing triethylamine, tetraethylammonium hydroxide, and morpholine, which leads to unique properties for support and production cost reduction. Meanwhile, Cu/SAPO-34, Fe/SAPO-34, and Cu-Fe/SA...

Gas turbines operate at exhaust gas temperatures exceeding 500 °C. Vanadium-based catalysts encounter challenges in NH₃-SCR denitrification due to vanadium volatilization and titanium dioxide support phase transition at high temperatures. This re...

The main goal of the study was the development of effective catalysts for the low-temperature selective catalytic reduction of NO with ammonia (NH₃-SCR), based on ferrierite (FER) and its delaminated (ITQ-6) and silica-intercalated (ITQ-36) forms mod...

Selective catalytic reduction of nitrogen oxides with NH₃ (NH₃-SCR) was investigated deeper and deeper with poisoning factors such as H₂O, SO₂, heavy metals, etc. In order to remove the reheating process before the SCR reactor, the application trend...

The application of iron oxide to NH₃-SCR is attractive but largely hindered by its poor acid properties, and surface sulfation is proven to be a prominent way of enhancing the acidity. As such, the method of enriching the sulfate species on iron oxid...

Ferrierites and their delaminated forms (ITQ-6), containing aluminum or titanium in the zeolite framework, were synthetized and modified with copper by an ion-exchange method. The obtained samples were characterized with respect to their chemical com...