Fast Colorimetric Assay for Screening NSR Catalyst

The NSR (NOx storage and reduction) technology is one of the most promising methods for removing NOx from next-generation lean-burn and diesel engines. Three major drawbacks, including the low temperature activity, the catalyst sulfur tolerance and the use of the large amount of the noble metals for the commercial application of NSR catalytic system, may be resolved by the development of a better catalytic system through a fast assay method in line with the combinatorial chemistry technique. The colorimetric method is the most effective way for screening a large number of the catalyst samples at once, although an appropriate dye for revealing the color specific to NOx should be examined in advance. A knowledge-based colorimetric methodology for screening a better NSR catalyst by combinatorial approach has been developed and validated by the experimental results determined by means of traditional, time-consuming techniques such as TPD.