Chemiluminescence analyzer of NO as a high-throughput screening tool in selective catalytic reduction of NO

A chemiluminescence-based analyzer of NO gas species has been applied for high-throughput screening of a library of catalytic materials. The applicability of the commercial NO analyzer as a rapid screening tool was evaluated using selective catalytic reduction of NO gas. A library of 60 binary alloys composed of Pt and Co, Zr, La, Ce, Fe or W on Al₂O₃ substrate was tested for the efficiency of NO removal using a home-built 64-channel parallel and sequential tubular reactor. The NO concentrations measured by the NO analyzer agreed well with the results obtained using micro gas chromatography for a reference catalyst consisting of 1 wt% Pt on γ-Al₂O₃. Most alloys showed high efficiency at 275 °C, which is typical of Pt-based catalysts for selective catalytic reduction of NO. The screening with NO analyzer allowed to select Pt-Ce₍ (X=1-3) and Pt-Fe₍₂₎ as the optimal catalysts for NO removal: 73% NO conversion was achieved with the Pt-Fe₍₂₎ alloy, which was much better than the results for the reference catalyst and the other library alloys. This study demonstrates a sequential high-throughput method of practical evaluation of catalysts for the selective reduction of NO.