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As the official proposal for emission regulation Euro 7 has been released by European Commission, PN above 10nm is taken into consideration for the ultrafine particulate emissions control. The challenges of GPF filtration efficiency emerge for the light-duty manufactures to meet the future emission standards. In the present study, a China 6 compliant vehicle was tested to reveal its performance over the China 6 standards and potential to meet the upcoming Euro 7. Three GPF product types (Gen 1, Gen 2, and concept Gen 3) were mounted to the tested vehicle. WLTC tests were conducted on chassis dynamometer in laboratory as well as a self-designed aggressive cycle (“Base Cycle”) tests. To explore the GPFs performance for PN emissions above 10nm against the proposed limit 6.0E11 #/km, PN emission above 10nm were measured in our laboratory tests for both engine out and tailpipe as well as the PN emission above 23nm. In addition, worst case RDE tests were carried out on the real road with PEMS. It was found that, when including particles down to 10nm, further improvement is needed for the current system, and the Gen 2 and concept Gen 3 products could be a promising path to meet the proposed standards with much higher filtration efficiency. Combined with possibly further extended RDE boundary conditions in Euro 7, the test results suggested that higher filtration efficiency filter products are likely required to comply with the tightened emission regulations.

Gasoline particulate filter (GPF) is a cost-effective solution to particle number emissions from gasoline direct injection vehicles. Filtration efficiency, as a key parameter of GPF, was usually assessed at chassis level over regulatory drive cycles. However, the promulgation of real driving emission (RDE) requirements in the EU and Chinese regulations necessitates evaluations based on non-legislative cycles to guarantee the on-road emissions are compliant to regulatory requirements. In this research, two aggressive drive cycles, RTS95 at 23degC and modified RDE at 0degC, were complemented to the WLTC to evaluate the filtration efficiency of a catalyzed GPF (cGPF) in fresh conditions to obtain the so-called "worst-case" filtration efficiency. In the WLTC, RTS95, and simulated RDE tests, the filtration efficiency of the test cGPF was 51.1%, 41.3%, and 85.1% respectively. In the simulated RDE test, the test cGPF filtrated solid particles with a diameter above 23 nm and 10 nm at a similar efficiency. Increased filtration efficiency with heavier soot load could offset the relatively low filtration efficiency in cold-start and warm-up durations, hence the filtration efficiency for a clean cGPF showed higher sensitivity to cycle length over driving dynamics and testing temperature. In acceleration events with cGPF mounted, the particle diameter where number concentration peaked decreased as the engine warmed up. In deceleration events, bimodal and trimodal particle number size distributions with much lower concentrations were observed.

This paper presents the latest progress in high porosity filter product development for the 4-way application as well as the corresponding property and performance attributes. Two new compositions, Dev-HPl and Dev-HP2, at 72% porosity with median pore sizes of 17 μm and 20 μm are identified and under development. From composition development, narrow pore size distribution and good pore connectivity were achieved in comparison to the previous version of high porosity filters, Dev-EC, and also the standard commercial product, DumTrap® CO. As a result, the pressure drop performance has been significantly improved while a high filtration efficiency of more than 95% has been preserved (artificial soot lab test). The detailed physical property and performance data for these two new 72% porosity filters (vs. Dev-EC and DuraTrap® CO) are discussed. It is anticipated that significantly improved pore microstructure and high wall permeability will allow high catalyst loading in the wall for the 4-way catalyst application.

A family of high surface area carbon honeycomb substrates has been developed for a variety of environmental applications. This technology is based on synthetic carbon precursors combined with a ceramic backbone to producestrong, abrasion resistant and durable carbon structures. These structures do not contain any binders and as a result are highly durable to solvent attack and are also highly electrically conductive. These structures contain from 5-95% carbon, which can then be activated to obtain surface areas in excess of 1000 m 2 /g. In addition, catalyst precursors can be added to the carbon precursors to achieve catalyst dispersed in-situ within the carbon structure. Them substrates are ideal candidates for industrial air pollution control, water purification, catalyst support, capacitive deionization and other applications. The materials and processing for these high surface area canon substrates will be discussed. In addition, two applications will be discussed in more detail- their use as catalyst supports and in capacitive deionization of water.

A family of cordierite DPF filters were developed and studied for their efficacy for catalyzed soot filter applications. In addition to porosity and median pore size of DPF filters, breadth of pore size distribution, microstructure, and pore connectivity have a profound influence not only in filter performance (pressure drop, catalyst coatability, and filtration efficiency) but also on mechanical and physical properties. Through filter material composition development, optimum values for the %porosity, median pore diameter, and breadth of the pore size distribution for minimizing pressure drop have been identified, leading to the development of a new family of high-porosity cordierite diesel particulate filters that possess a unique combination of high filtration efficiency, high strength, and very low clean and soot-loaded pressure drop in both the catalyzed and non-catalyzed states. By controlling the microstructure, the impact of the catalyst on pressure drop has been minimized. Soot-loaded pressure drops of these new filters in their catalyzed state are less than 50% of other catalyzed commercial filters with the same cell geometry. In contrast, large pore size and high porosity filters raise concerns of low filtration efficiency and low mechanical strength at both catalyzed and uncatalyzed states. Addition of catalyst into the filters seems to have little or no impact on filter filtration efficiency, static mechanical and thermal properties.