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This paper describes how the analytical methodology for fuels and exhaust gases was selected and developed for the experimental sectors of the EPEFE study. It covers the selection of standard test methods for fuels analysis and addresses how round-robin exercises in non-standard areas of fuels analysis were designed, organised, monitored and reviewed, and then used to define the approach to (and the scope of) the speciated fuel analyses. The paper also addresses how the exhaust gas analysis was designed in relation to emissions testing methodology. The means used to evaluate and, where necessary, optimise the exhaust gas speciation capabilities of participating laboratories, and in which round-robin activities were a key element, are also explained.

A commercial NOx-storage catalyst for gasoline applications containing Ba/CeO2/Al2O3, platinum, palladium and rhodium has been sulfated on the engine bench at 390 and 510°C with a nominal exposure of 1.3 g sulfur/liter catalyst. Lower exposures proved too low to have a notable impact on the catalytic performance. At 390°C the sulfur is completely adsorbed while at 510°C only partial adsorption is being observed. Sulfur is mainly deposited at the catalyst inlet thereby shielding the downstream region. Desulfation on synthetic gas bench at 700°C leads to a partial removal of the sulfur. The residual sulfur is more evenly distributed along the length of the catalyst compared to the sulfur profile in the sulfated catalyst. This causes an improvement of the NOx-activity at the inlet side while the NOx-performance at the outlet side decreases after desulfation.