Low-temperature propene combustion over Pt/K-βAl2O3 electrochemical catalyst: Characterization, catalytic activity measurements, and investigation of the NEMCA effect

Studies of characterization and electrochemical promotion of the electrochemical catalyst Pt/K-βAl2O3 for low-temperature propene combustion are reported for the first time. Characterization of Pt/K-βAl2O3 by surface titration, SEM, and XRD revealed useful information about the electrochemical catalyst. On the other hand, it was found that Pt/K-βAl2O3 can be strongly promoted at low temperature for propene oxidation under both near-stoichiometric and oxygen-rich conditions. For instance, under C3H6/O2: 2000 ppm/7% at 200 °C, a rate enhancement ratio (ρCO2ρCO2) of 7 was achieved under application of VWR=−2 VVWR=−2 V, increasing propene conversion from 10 to 70%. In addition, the origin of the NEMCA effect was investigated using cyclic voltammetry along with CO2 analysis as well as FTIR measurements and SEM-EDX analysis. These techniques showed that the presence of more stable and effective promoter phases (potassium oxides and superoxides) were responsible for both a permanent NEMCA effect and a higher promotional phenomenon in comparison to sodium conductors.