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Spatially resolved in situ measurements of transient species breakthrough during cyclic, low-temperature regeneration of a monolithic Pt/K/Al2O3 NOx storage-reduction catalyst

“…The cycle-averaged NO x conversion at the 1/4 catalyst position was slightly greater with CO reductant compared to H 2 , and these were both greater than that obtained with the H 2 /CO reductant. Li et al have reported that CO is a more effective reductant than a H 2 /CO mixture or C 3 H 6 at 300 8C [22]. However, the differences observed in this study were relatively small and it would be difficult to assert that there are major global efficiency differences for CO and H 2 at 300 8C.…”

Thermal decomposition of bulk and supported barium nitrate

“…Though first developed for lean burn gasoline engines [3][4][5][6][7] NSR catalysts are now more widely investigated for NO x control in diesel vehicles [8,9]. The operating mechanism of NSR catalysts has attracted considerable attention (see for example [10][11][12][13]) and involves the interaction of NO 2 with an adsorber component under oxidising conditions with a periodic rich excursion to decompose and reduce the stored NO x species. The most usual storage materials are composed of a precious metal, preferably Pt for its ability to oxidize NO, an alkali or alkaline earth oxide (typically baria) which can readily form a nitrate and a suitable high surface area support.…”

Thermal Autoignition of Aqueous Urea Ammonium Nitrate as a Function of Equivalence Ratio, Water Content, and Nitrogen Pressure

“…The effect of the equivalence ratio on the AIT of UAN was investigated under fuel‐rich conditions (1< φ ≤2.5). Such conditions were tested because of their usefulness in catalytic combustion/effluent treatment . An increase of the φ of UAN changes the urea to AN content ratio and results in higher AIT values (Figure ).…”

“…Such conditions were tested because of their usefulness in catalytic combustion/effluent treatment. [13][14][15] An increaseo ft he f of UANc hanges the urea to AN content ratio and results in higher AIT values ( Figure 4). This means that fuel-rich mixtures require higher temperaturesa nd therefore more heat to achieve thermal autoignition.T he simulated AIT values were in good agreement with the experimental results throughout the f range tested (Figure 4).…”

“…Values highera nd lower than unity correspondt or ich and lean mixtures,r espectively.R ich conditions are used for catalytic combustion, ignition, and aftertreatment processes. [13][14][15] Thed eterminationo ft he AIT of UANi nafuel-riche nvironmenti sn ecessary to identify the conditions requiredt oe nable the thermal autoignition of the fuel at f> 1. To the best of our knowledge,t here are no studies on the effect of rich equivalence ratios on UANi gnition.…”