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The new emission regulations in Europe, EU 6 will promulgate more realistic driving conditions with more stringent HC, CO, NOx and particulate emissions. This legislation will also include the WLTP (Worldwide harmonized Light vehicles Test Procedure) cycle for CO2 measurements and a new requirement called “Real-Driving-Emissions” (RDE) as well. The RDE requirement is to ensure modern vehicles comply with the legislation under all conditions of normal driving. More robust aftertreatment solutions are needed to meet these new requirements. This work introduces an improved three-way catalyst (TWC) for gasoline engines for these new regulations. It is tested under static and dynamic conditions and on several engines and vehicles with various drive cycles. It offers better thermal stability combined with lower backpressure than former TWC generations.

The diesel oxidation catalysts (DOC) having high purification performance to the exhaust gas at low temperatures were investigated. In this paper two main technological improvements from conventional DOC are shown. First is forming Pt/Pd composite particles in order to suppress sintering of precious metal under high thermal aging condition. This generating Pt/Pd composite and the effect were exemplified by TEM-EDS and XRD analysis. Second is adjusting electric charge of Pt/Pd surface to reduce interaction between Pt/Pd and carbon monoxide (CO) by modifying the support material components. Adjusting electric charge of Pt/Pd surface by applying new support material could cancel CO poisoning at Pt/Pd surface. Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) studies suggested that improved support material is more suitable for CO oxidation at a low temperature based on the concept.

To meet future emission levels the industry is trying to reduce tailpipe emissions by both, engine measures and the development of novel aftertreatment concepts. The present study focuses on a joint development of aftertreatment concepts for gasoline engines that are optimized in terms of the exhaust system design, the catalyst technology and the system costs. The best performing system contains a close-coupled catalyst double brick arrangement using a new high thermal stable catalyst technology with low precious metal loading. This system also shows an increased tolerance against catalyst poisoning by engine oil.

Besides the further reduction of the harmful gaseous emissions (HC, CO and NOx) to reach upcoming emission limits, the discussion on lowering the CO₂ emissions is omnipresent. From engine development point of view further optimization of the stoichiometric-operated gasoline engine as well as the introduction of lean-operated engines are the main development trend. The emission control system can support the engine development by dedicated catalyst technologies as presented in this paper. A new family of TWC technologies offers to tune the catalyst system to the engine performance and the back pressure requirement - which helps to reduce CO₂ emissions. In addition these technologies show improved performance in HC, CO, NOx light-off, and in CO and NOx conversions under dynamic conditions - this again can positively impact the CO₂ emissions as less harsh heating strategies for cold start is required.

Due to benefits from the use of electric power, Hybrid Electric Vehicles (HEVs) and Plug-in Hybrid Electric Vehicles (PHEVs) are regarded to be superior over conventional Internal Combustion Engine (ICE) only vehicles in fuel economy and emissions. However, recent studies find out that this is not always true. On certain conditions, hybrid vehicles can be even more polluted. In order to identify these challenges and develop catalysts to meet more stringent emission requirement in the future, e.g. Euro 7, for hybrid application, as a part of our xHEV project, this study includes exclusively extensive investigation on a latest Euro 6d temp Parallel PHEV.

Diesel Oxidation Catalyst in conjunction with large frontal area substrates is a key element in HDV Diesel emission control systems. This paper describes and reviews tests on a set of various Diesel Oxidation Catalyst configurations (for example cell densities), all with the same catalyst coating. The Diesel Oxidation Catalyst specimens were subjected to the European Stationary Cycle (ESC), the European Transient Cycle (ETC), and the US heavy duty Federal Test Procedure (US FTP). The focus was to study relative emissions, pressure drop, and light-off performance. All tests were conducted using the same Detroit Diesel Series 60 engine operating on ultra low sulfur diesel fuel. In addition to this, the exhaust was regulated so that the backpressure on the engine, upstream of the catalyst was also the same for all catalysts.

The oil ash accumulation on modern three way catalyst (TWC) as well as its influence on catalyst deactivation is evaluated as a parameter of oil consumption, kind of oil additive compound and additive concentration. The oil ash accumulation is characterized by XRF and SEM/EDX in axial direction and into the washcoat depth of the catalyst. The deposition patterns of Ca, Mg, P and Zn are discussed. The catalytic activity of the vehicle and engine bench aged catalysts is measured by performing model gas tests and vehicle tests, respectively. The influence of oil ash accumulation on the lifetime emission behavior of the vehicle is discussed.

Stringent emissions standards with 95+% conversion efficiency requirements call for advanced ceramic catalyst supports with thinner walls, higher cell density and optimum cell shape. The extrusion technology for cellular ceramics has also made significant progress which permits the manufacture of advanced catalyst supports. Similarly, modifications in cordierite chemistry and the manufacturing process have led to improved microstructure from coatability and thermal shock points of view. The design of these supports, however, requires a systems approach to balance both the performance and durability requirements. Indeed as the wall gets thinner, the contribution of washcoat becomes more significant in terms of thermal mass, heat transfer, thermal expansion, hydraulic diameter and structural stiffness - all of which have an impact on performance and durability. For example, the thinner the wall is, the better the light-off performance will be.

This summary covers representative developments from 2008 in diesel regulations, engine technology, and NOx, particulate matter (PM), and hydrocarbon (HC) control. Europe is finalizing the Euro VI heavy-duty (HD) regulations for 2013 with the intent of technologically harmonizing with the US. A new particle number standard will be adopted. California is considering tightening the light-duty fleet average to US Tier 2 Bin 2 levels, and CO2 mandates are emerging in Europe for LD, and in the US for all vehicles. LD engine technology is focused on downsizing to deliver lower CO2 emissions, enabled by advances in boost and EGR (exhaust gas recirculation). Emerging concepts are shown for attaining Bin 2 emission levels. HD engines will make deNOx systems optional for even the tightest NOx standards, but deNOx systems enable much lower fuel consumption levels and will likely be used. NOx control is centered on SCR (selective catalytic reduction) for diverse applications.

The paper summarizes the key developments in diesel emission control, generally for 2005. Regulatory targets for the next 10 years and projected advancements in engine technology are used to estimate future emission control needs. Recent NOx control developments on selective catalytic reduction (SCR), lean NOx traps (LNT) and lean NOx catalysts (LNC) are then summarized. Likewise, the paper covers important recent developments on diesel particulate filters (DPFs), summarizing regeneration strategies, new filter and catalyst materials, ash management, and PM measurement. Recent developments in diesel oxidation catalysts are also briefly summarized. Finally, the paper discusses examples of how it is all pulled together to meet the tightest future regulations.

Driven mainly by tightening of regulations, advance diesel emission control technologies are rapidly advancing. This paper will review the field with the intent of highlighting representative studies that illustrate the state-of-the-art. First, the author makes estimates of the emission control efficiency targets for heavy and light duty applications. Given the emerging significance of ultrafines to health, and to emission control technologies, an overview of the significant developments in ultrafine particulate science is provided, followed by an assessment of filter technology. Major deNOx catalyst developments, in addition to SCR and LNT progress is described. Finally, system integration examples are provided. In general, progress is impressive and studies have demonstrated that high-efficiency systems are within reach in all sectors highway vehicle sectors. Engines are making impressive gains, and will increase the options for emission control.

NOx storage catalyst systems (or lean NOx trap, LNT) will most likely play an important role in meeting the future global Diesel emission standards. DaimlerChrysler introduced in 2006 the E 320 BLUETEC Diesel, which represents the first Clean Diesel car with NOx storage catalysts in North America [1]. The vast number of different applications result in a wide spectrum of different operating conditions for the LNT systems. Each of those different environments requires a fine-tuning of the catalyst's properties, particularly sulfur release properties and thermal durability. High average exhaust temperatures typical for a placement close to the engine require high thermal durability. Higher desulfation temperatures are acceptable in such a case since those temperatures are easier to achieve in such a configuration.

This paper describes a study of ternary V2O5/WO3/TiO2 SCR catalysts coated on standard Celcor® and new highly porous cordierite substrates. At temperatures below 275°C, where NOx conversion is kinetically limited, high catalyst loadings are required to achieve high conversion efficiencies. In principle there are two ways to achieve high catalyst loadings: 1. On standard Celcor® substrates the washcoat thickness can be increased. 2. With new highly porous substrates a high amount of washcoat can be deposited in the walls. Various catalyst loadings varying from 120g/l to 540 g/l were washcoated on both standard Celcor® and new high porosity cordierite substrates with standard coating techniques. Simulated laboratory testing of these samples showed that high catalyst loadings improved both low temperature conversion efficiency and high temperature ammonia storage capacity and consequently increased the overall conversion efficiency.

Future NOx-emission standards for diesel engines imply an after treatment system, e.g. in the form of an NH3-SCR system. For the technical realization a sound understanding of the catalytic processes is mandatory. To gain this knowledge a model of the SCR of NO with NH3 on Fe zeolite catalysts has been developed on the basis of a transient test cycle. The model is able to map the performance of the catalyst both under steady state and transient conditions. As practical examples the model is used to parameterize lookup tables and to compare different formats of lookup tables in terms of suitability for a urea dosage system.

An axisymmetric finite element model is generated to simulate the windshield glass damage propagation subjected to impact loading of a flying object. The windshield glass consists of two glass outer layers laminated by a thin poly-vinyl butyral (PVB) layer. The constitutive behavior of the glass layers is simulated using brittle damage mechanics model with linear damage evolution. The PVB layer is modeled with linear viscoelastic solid. The model is used to predict and examine through-thickness damage evolution patterns on different glass surfaces and cracking patterns for different windshield designs such as variations in thickness and curvatures.

The development of diesel powered passenger cars is driven by the enhanced emission legislation. To fulfill the future emission limits there is a need for advanced aftertreatment devices. A comprehensive study was carried out focusing on the improvement of the DOC as one part of these systems, concerning high HC/CO conversion rates, low temperature light-off behaviour and high temperature aging stability, respectively. The first part of this study was published in [1]. Further evaluations using a high temperature DPF aging were carried out for the introduced systems. Again the substrate geometry and the catalytic coating were varied. The results from engine as well as vehicle tests show advantages in a highly systematic context by changing either geometrical or chemical factors. These results enable further improvement for the design of the exhaust system to pass the demanding emission legislation for high performance diesel powered passenger cars.

To meet tightening emissions standards, alternate pollution abatement technologies are necessary, such as an In-Line Adsorber (ILA) system. The ILA has a first catalyst, an adsorber, and a second catalyst. A diverter directs exhaust gas through the adsorber to capture unconverted hydrocarbons until the first catalyst reaches light-off temperature. The ILA system was designed so that the second catalyst becomes active concurrent with the adsorber hydrocarbon desorption. The system was evaluated using the FTP test with two different secondary air strategies on 3.8 liter V6 and 4.0 liter V8 vehicles. The ILA system performance consistently reduced ∼50-60% of cold start hydrocarbon emissions. This study examined a simplified ILA system designed to operate with a commercial secondary air pump powered by the engine.

In lean burn engines, the conventional automotive catalyst is ineffective in reducing harmful nitric oxide (NOx) wastes. This study has investigated the use of different materials with metal additives as supports for effective NOx- controlling lean burn catalysts. A series of zeolite (ZSM-5) honeycomb samples were prepared via extrusion with low concentrations of transition metals. Samples were also impregnated with Pt to determine the effect on the catalytic activity. NOx and hydrocarbon conversion under simple lean conditions were measured in a temperature-controlled fixed bed reactor. Ethylene and Propylene, both highly selective NOx reductants, were used separately as the hydrocarbon species. Results have revealed that single and double component zeolites containing Ni, Mn, Cu, and Ag are highly effective in reducing NOx. When these same samples were impregnated with Pt, they achieved conversion rates up to 100% at temperatures less than 300°C at a space velocity of 7000 h-1.

This study investigated the performance of various designs of ceramic monolithic catalyst supports for automotive emissions control. A test was conducted to examine the relationship of monolith volume, precious metal loading, cell density, and monolith frontal area on FTP emissions. The conclusion is that higher volume and/or higher cell density monoliths will yield improved catalytic performance using equal or less total precious metal per converter.

The effect of web thickness on emission performance, pressure drop, and mechanical properties was investigated for a series of catalyzed ceramic monolith substrates having cell densities of 900, 600 and 400 cpsi. As expected, thinner webs provide better catalyst light off performance and lower pressure drop, but mechanical strength generally decreases as web thickness is reduced. Good correlations were found between emission performance and geometric parameters based on bare and coated parts. An improved method for estimating the effects of cell density and web thickness on bare substrate strength is described, and the effect of porosity on material strength is also examined. New mechanical strength correlations for ceramic honeycombs are presented. The availability of a range of ceramic product geometries provides options for gasoline exhaust emission design and optimization, especially where increased levels of performance are desired.