Promoted Decomposition of NO_x in Automotive Diesel-like Exhausts by Electro-Catalytic Honeycombs

Abstract

NO and NO2 (collectively called NOx) are major air pollutants in automotive emissions. More effective and easier treatments of NOx than those achieved by the present methods can offer better protection of human health and higher fuel efficiency that can reduce greenhouse gas emissions. However, currently commercialized technologies for automotive NOx emission control cannot effectively treat diesel-like exhausts with high NOx concentrations. Thus, exhaust gas recirculation (EGR) has been used extensively, which reduces fuel efficiency and increases particulate emission considerably. Our results show that the electro-catalytic honeycomb (ECH) promotes the decomposition of NOx to nitrogen and oxygen, without consuming reagents or other resources. NOx can be converted to nitrogen and oxygen almost completely. The ECHs are shown to effectively remove NOx from gasoline-fueled diesel-like exhausts. A very high NO concentration is preferred in the engine exhaust, especially during engine cold-start. Promoted NOx decomposition (PND) technology for real-world automotive applications is established in this study by using the ECH. With PND, EGR is no longer needed. Diesel-like engines can therefore achieve superior fuel efficiency, and all major automotive pollutants can be easily treated due to high concentration of oxygen in the diesel-like exhausts, leading to zero pollution.

Mechanistic Study of Gas-Phase Controlled Synthesis of Copper Oxide-Based Hybrid Nanoparticle for CO Oxidation

“…Other components (e.g., Al 2 O 3 and CeO 2 in this study) can be used to disperse Cu x O to maximize the active surface area, to increase the number of active sites for the multiple types of reactants, and/or to improve stability in operation. The Cu x O-based hybrid NPs have gained huge research potential in the areas of water–gas shift reactions , and selective catalytic reduction of nitrogen oxides. − The Cu x O-based hybrid NPs can be obtained using the designed material, which enables a variety of catalysis in the nanostructure with high activity and stability …”

Synergistic Inorganic/Inorganic Hybrid Approach for Fabricating a BTX Gas Adsorbent with High Performance and Thermal Stability

“…4 Furthermore, BTX gases can contribute to severe ozone depletion in the stratosphere, which can further accelerate the greenhouse effect. 5 Therefore, significant efforts should be urgently devoted to alleviate the emission of toxic VOCs from industries and automobiles. 6,7 The use of adsorbents is considered the most cost-effective and easily accessible method to remove lipophilic BTX hydrocarbons.…”

“…Such aromatic VOCs have a high potential to generate ozone molecules and hydroxyl radicals in the troposphere, which can be precursors for the formation of fine inhalable micron-sized particulate matter (PM2.5) in the air . Furthermore, BTX gases can contribute to severe ozone depletion in the stratosphere, which can further accelerate the greenhouse effect . Therefore, significant efforts should be urgently devoted to alleviate the emission of toxic VOCs from industries and automobiles. , …”

Highly Efficient NO Decomposition via Dual-Functional Catalytic Perovskite Hollow Fiber Membrane Reactor Coupled with Partial Oxidation of Methane at Medium-Low Temperature

“…At the same time, NO x are extremely toxic to human body. NO x are mainly produced by automobiles and stationary power plants. − Currently, several methods have been widely applied for NO x removal, such as selective catalytic reduction (SCR), − selective noncatalytic reduction (SNCR), nonselective catalytic reduction (NSCR), and direct NO x decomposition. ,− Both SCR and SNCR use NH 3 or urea as a reductant to reduce NO x to N 2 and water. For SCR, V 2 O 5 –WO 3 (MoO 3 )/TiO 2 has been widely employed as the catalyst to control the emission of NO from stationary coal fired power plants or diesel engine at around 200–400 °C. ,,,− In contrast, the catalyst absent SNCR process incurs low capital cost, yet the NO x removal efficiency is lower than SCR and the operating temperature is as high as 800–1100 °C .…”