In situ fabrication of Au–CoFe2O4: an efficient catalyst for soot oxidation

Abstract

Diesel soot particulate is one of the main sources of air pollution, which should be eliminated effectively to minimize the carcinogenic and lethal effect of air. Herein, an effort has been made to synthesize Au–CoFe2O4 nanocomposite by a facile route and use as an effective catalyst for soot oxidation. The physicochemical properties of Au–CoFe2O4 were carried out through SEM, EDX mapping, HRTEM, XRD, XPS, hydrogen temperature-programmed reduction (H2-TPR), and NO temperature-programmed oxidation (NO-TPO). Au–CoFe2O4 catalyst showed a remarkable catalytic property for soot oxidation in both NO + O2 and O2 owing to the formation of oxygenated species that enhanced the oxidizing properties of the catalyst. The CoFe2O4 composite showed a remarkable and stable catalytic property for soot oxidation, and low T50 (50% soot conversion) 411 °C value has been achieved in the presence of O2. While as we introduced gold (Au) to form Au–CoFe2O4 then its catalytic performance for soot oxidation was found to be tremendously increased to T50 341 °C owing to the formation of surface-oxygenated species that enhanced the oxidizing properties of the catalyst surface. The durability performance of the catalyst including reusability, this catalyst showed even better soot oxidation activity after sulfur and hydrothermal aging. Owing to the tremendous soot oxidation activity, this catalyst can be used as an environmentally friendly and efficient soot oxidizer for the removal of soot.