With a PTD Detector

Another type of IR gas-sensor has been reported by Cong et al. for the HTS of ethane ODH [12, 13]. They used a photothermal deflection (PTD) detector with a mass spectrometer because an electron-impact mass spectrometer cannot detect C2H4 concentrations at the ppm level in the presence of high concentrations of 

The sensitivity of the PTD detector toward C2H4 is below 0.1 ppm. The detector can estimate ethylene yields of each reaction within 90 s. 

The library, on a quartz substrate, consisted of almost 50 catalysts (ca. 200 pg). Each catalyst was heated by C02-laser irradiation to between 300 and 400 °C before reaction. Then, a gas mixture of N2, C2H6 and 02 (molar ratio 5 4 1) was blown to each catalysts. A library consisting of Mo-V-Nb with 10% compositional increments per matrix element was prepared and screened. The binary catalysts of Mo-V-O show low conversion and ethylene selectivity. The presence of Nb increases both activity and selectivity dramatically. The superior catalysts found by the screening were scaled up and showed similar catalysis. 

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