Impact of test cycle on mass, number and particle size distribution of particulates emitted from gasoline direct injection vehicles.

Ageing of automotive catalysts is associated to a loss of their functionality and ultimately to a waste of precious resources. For this reason, understanding catalyst ageing phenomena is necessary for the design of long lasting efficient catalysts. The present work has the purpose of studying in depth all the phenomena that occur during ageing, in terms of morphological modification and deactivation of the active materials: precious metal particles and oxidic support. The topic was deeply investigated using specific methodologies (FT-IR, CO chemisorption, FE-SEM) in order to understand the behavior of metals and support, in terms of their surface properties, morphology and dispersion in the washcoat material. A series of commercial catalysts, aged in different conditions, have been analyzed, in order to find correlations between real and simulated ageing conditions. The characterization highlights a series of phenomena linked to the deactivation of the catalysts. Pd nanoparticles undergo a rapid agglomeration, exhibiting a quick loss of dispersion and of active sites with an increase of particles size. The evolution of the support allows highlighting also the contribution of chemical ageing effects. These results were also correlated with performance tests executed on synthetic gas bench, underlining a good correspondence between vehicle and laboratory aged samples and the contribution of chemical poisoning to vehicle aged ones. The collected data are crucial for the development of accelerated laboratory ageing protocols, which are instrumental for the development and testing of long lasting abatement systems.

https://www.mdpi.com/2073-4344/11/2/247/pdf

Characterization of the evolution of noble metal particles in a commercial three‐way catalyst: Correlation between real and simulated ageing

Estimating light-duty vehicles' contributions to ambient PM2.5 and PM10 at a near-highway urban elementary school via elemental characterization emphasizing rhodium, palladium, and platinum.

In recent times, the extinction of fossil fuel resources and emission of harmful pollutants have persuaded the researchers to obtain alternative and renewable fuels. Consequently, in the present experimentation, a ternary fuel blend was acquired and analysed in a modified turbocharged gasoline direct injection (GDI) engine as a feasible alternative to neat fossil fuel. Experiments were carried out using a blend of 8% n-butanol and 8% mass fraction of hydrogen with gasoline fuel at city transport speed mode under stoichiometric and air-fuel ratio of 1.0. Butanol and hydrogen were blended with the gasoline due to their satisfying thermodynamic properties and combustion reactivity. The result shows gradual reduction of particles emitted with n-BH16 by 1.06 × 1011 particles/hr as compared to n-BH00 at 1.89 × 1012 particles/hr. For all fuels, the smallest particles measured by Engine Exhaust Particle Sizer (EEPS) were no longer detectable at phase 2 from 548 s to ~789 s due to low concentrations. However, the gaseous emission of the n-BH16 fueled engine varies with 28 g/kW.h decrement in fuel consumption (FC), while increasing hydrocarbon (HC) emission. As a result, ultra-particles decreased in nucleation mode, which in-turn lead to minimum combustion duration and cylinder gas pressure. Adaptation of n-BH16 fuel blend in light-duty GDI engines might serve as a potential to meet the new particulate emission regulations and improve toxic air contaminant.

Characteristics of ultrafine particle emission from light-vehicle engine at city transport-speed using after-treatment device fueled with n-butanol-hydrogen blend

Investigation on sub-23 nm particles and their volatile organic fraction (VOF) in PFI/DI spark ignition engine fueled with gasoline, ethanol and a 30 %v/v ethanol blend

The main system to reduce engine emissions of gasoline-fueled vehicles is represented by the three-way catalyst (TWC). The main catalyst of this system usually works in extreme conditions which induce a phenomenon called thermal ageing, the major way of catalyst deactivation. Increasingly stringent emissions standards require not only high efficiency in emissions abatement, but also maintaining the performances at high vehicle mileage. Automotive manufacturers need to accelerate testing methods and that should be representative of the ageing on vehicle, at the minimum expense in terms or time and cost. In order to develop and validate such methods, a deep understanding of all the microscopic processes associated with ageing is necessary. In this work we discuss a methodology for the study of the static thermal ageing of a commercial TWC. A specific washcoat extraction method was developed, and the separated washcoat was analyzed using XRD, TEM microscopy, Raman Spectroscopy and BET. These techniques allow to follow the main morphological and chemical changes in the sample: the loss of porosity, the evolution of crystalline phases and metal particles sintering and oxidation. The potential of Raman spectroscopy for the spatially resolved analysis of ageing is also highlighted. The results allowed to understand the process that involve the washcoat at high temperature.

Thermal Ageing Effects in a Commercial Three-Way Catalyst: Physical Characterization of Washcoat and Active Metal Evolution

Sub-23 nm Particle Emissions from Gasoline Direct Injection Vehicles and Engines: Sampling and Measure

Recently, the automotive industry has experienced rapid growth in powertrain electrification, with more and more battery electric vehicles (BEV) and hybrid electric vehicles being launched. Lithium-ion batteries play an important role due to their high energy capacity and power density, however they experience high heat generation in their operation, and if not properly cooled it can lead to serious safety issues as well as lower performance and durability. In that way, good prediction of a battery behavior is crucial for successful design and management. This paper presents a 1D electrochemical model development of a 144 Ah prismatic rolled cell using the GT-Autolion software with a pseudo 2D approach. The model correlation is done at cell level comparing model results and test data of cell open circuit voltage at different temperatures and voltage and temperature profile under different C-rates and ambient temperatures. After the cell level validation, a lumped battery pack model was submitted to different drive cycles: EPA, CLTC-P and WLTC having the battery current as input and comparing battery voltage and SOC. The cell level model presented good correlation with test data and the battery model proved capable of accurately make performance predictions. This model be used for further advanced investigations, such as cell degradation, thermal runaway and gas generation.

Transient Electrochemical Modeling and Performance Investigation Under Different Driving Conditions for 144Ah Li-ion Cell with Two Jelly Rolls

PLATIRUS project has received funding from the European Union’s Horizon 2020 Research and Innovation programme under Grant Agreement n° 730224.

Platinum Group Metals Recovery Using Secondary Raw Materials (PLATIRUS): Project Overview with a Focus on Processing Spent Autocatalyst

The production of new automotive catalytic converters requires the increase of the quantity of Platinum Group Metals in order to deal with the strict emission standards that are imposed for vehicles. The use of PGMs coming from the recycling of spent autocatalysts could greatly reduce the cost of catalyst production for the automotive industry. This paper presents the synthesis of novel automotive Three-Way Catalysts (PLTWC, Pd/Rh = 55/5, 60 gPGMs/ft3) and diesel oxidation catalysts (PLDOC, Pt/Pd = 3/1, 110 gPGMs/ft3) from recovered PGMs, without further refinement steps. The catalysts were characterized and evaluated in terms of activity in comparison with benchmark catalysts produced using commercial metal precursors. The small-scale catalytic monoliths were successfully synthesized as evidenced by the characterization of the samples with XRF analysis, optical microscopy, and N2 physisorption. Hydrothermal ageing of the catalysts was performed and led to a significant decrease of the specific surface area of all catalysts (recycled and benchmarks) due to sintering of the support material and metal particles. The TWCs were studied for their activity in CO and unburned hydrocarbon oxidation reactions under a slightly lean environment of the gas mixture (λ > 1) as well as for their ability to reduce NOx under a slightly rich gas mixture (λ < 1). Recycled TWC fresh catalyst presented the best performance amongst the catalysts studied for the abatement of all pollutant gases, and they also showed the highest Oxygen Storage Capacity value. Moreover, comparing the aged samples, the catalyst produced from recycled PGMs presented higher activity than the one synthesized with the use of commercial PGM metal precursors. The results obtained for the DOC catalysts showed that the aged PLDOC catalyst outperformed both the fresh catalyst and the aged DOC catalyst prepared with the use of commercial metal precursors for the oxidation of CO, hydrocarbons, and NO. The latter reveals the effect of the presence of several impurities in the recovered PGMs solutions.

Giovanna Nicol

Papers

Thermal Ageing Effects in a Commercial Three-Way Catalyst: Physical Characterization of Washcoat and Active Metal Evolution

Sub-23 nm Particle Emissions from Gasoline Direct Injection Vehicles and Engines: Sampling and Measure

Transient Electrochemical Modeling and Performance Investigation Under Different Driving Conditions for 144Ah Li-ion Cell with Two Jelly Rolls

Platinum Group Metals Recovery Using Secondary Raw Materials (PLATIRUS): Project Overview with a Focus on Processing Spent Autocatalyst

First of Its Kind Automotive Catalyst Prepared by Recycled PGMs-Catalytic Performance