Efficient catalytic combustion of propane at low temperature based on ignition effect caused by amorphous atomic-layer Pt clusters.

[Display omitted] • The ignition effect caused by atomic-layer Pt clusters was systematically studied. • The synergistic effect between exposed Pt atoms is remarkable: Gathering is a fire! • The E a of atomic-layer Pt clusters on TiO 2 much lower than that of single atom Pt. • The Pt/a-TiO 2 -AL catalyst could achieve more than 90 % of propane at 230 °C. • DFT calculation show that Pt/a-TiO 2 -AL had lower oxygen vacancy formation energy. Developing highly active catalysts for hydrocarbon combustion at low temperatures is paramount but yet challenging. The crystal form of carrier and the dispersion degree of active species have great influence on propane combustion catalysts, but its internal mechanism is still unclear. In this study, the amorphous atomic-layer Pt clusters (AL) and Pt single atoms (SA) on TiO 2 with various crystal phases were prepared and used as propane combustion catalysts, where the as-synthesized Pt/a-TiO 2 catalyst with atomic-layer Pt clusters exhibited better catalytic performance. The Pt/a-TiO 2 -AL could achieve a 90 % propane conversion (T 90) at 230 °C, with the highest reaction rate (39.57 × 10−7 mol g−1 s−1) and TOF value (7.72 × 10−2 s−1) at 240 °C. Kinetic studies showed that oxygen had a lower inhibitory effect on Pt/a-TiO 2 -AL compared to that on the Pt/p-TiO 2 -AL and Pt/r-TiO 2 -AL catalysts; simultaneously, the Pt/a-TiO 2 -AL catalyst presented lower apparent activation energy compared with Pt/a-TiO 2 -SA. DFT results showed that atomic-layer Pt clusters on TiO 2 had the lower formation energy of oxygen vacancy than Pt single atoms due to the synergistic effect between adjacent exposed Pt atoms in the fully exposed atomic-layer Pt clusters, which had a higher activation capacity for oxygen and thus accelerated propane combustion through the ignition effect (rapid activation of oxygen and rapid combustion of propane). Our primary results provide a promising approach for the creation of high-efficiency Pt-based catalysts, specifically tailored for the catalytic combustion of volatile organic compounds (VOCs). [ABSTRACT FROM AUTHOR]