NO oxidation over supported Pt: Impact of precursor, support, loading, and processing conditions evaluated via high throughput experimentation

This work summarizes the development and validation of a high throughput approach for automated design, synthesis, screening, and statistical analysis of supported heterogeneous catalyst systems. The catalytic oxidation of NO over supported Pt is used as a tractable case study to demonstrate consistency with published results and to generate a self-consistent set of data to evaluate the influence of synthesis and processing variables on catalytic performance using a five-factor two-level full factorial design-of-experiment (DOE). A novel approach is demonstrated for data descriptor generation whereby a simple model is used to extract kinetic parameters that can be used independently to evaluate performance, or used to calculate secondary performance metrics. The kinetic data obtained revealed a compensation effect for this reaction over Al2O3 and SiO2 supported Pt and is the first reported observation of this phenomenon for the oxidation of NO to NO2. Relative performance rankings of Pt supported on Al2O3 and SiO2 show an enhanced intrinsic rate for all the Pt/SiO2 catalysts. Both the Pt/Al2O3 and Pt/SiO2 systems were found to exhibit structure sensitivity, with the change in rate with average particle size appearing stronger for the Pt/Al2O3 system. Statistical analysis of the performance data was used to identify the main effects impacting the NO oxidation rate at 200 °C. The relative order of importance of the factors evaluated was found to be support > pretreatment > loading > calcination atmosphere > calcination temperature > precursor salt.