Decreasing the catalytic ignition temperature of diesel soot using electrified conductive oxide catalysts

Pursuance of low reaction temperatures deserves considerable efforts in regard to catalysis for energy efficiency. Catalytic soot combustion, the prevailing technology for reducing the emission of harmful diesel soot particulates, cannot occur efficiently at <200 °C exhaust temperature during frequent idling. Here, we report an electrification strategy aimed at decreasing the ignition temperature at which 50% of soot (T50) is converted at <75 °C using conductive oxides as catalysts, such as potassium-supported antimony-tin oxides. The performance achieved was far superior to that with conventional thermal catalytic soot combustion—generally with T50 >300 °C. Electrically driven release of lattice oxygen from catalysts is responsible for rapid soot ignition at low temperatures, while the opposite electrostatic fluidization between the conductive catalyst and soot particles accounts for improved catalyst–soot contact efficiency. The electrification process presents a promising strategy in meeting the common dilemma of reduction in vehicle emissions at low exhaust temperatures.