Nickel and cobalt transfigured natural clay: a green catalyst for low-temperature catalytic soot oxidation

Abstract

Soot particulates in engine exhausts pose a severe threat to the environment and human health – causing cancer, affecting the heart and lungs and drives metal processes. This study proposes a practical, real-world application of transition metal modified natural clay as an environmentally benign, low-cost, green catalyst for soot oxidation. Ni and Co (NC-Clay) incorporated natural clay catalysts were prepared by a simple wet impregnation method and meticulously characterized by different characterization techniques. The catalyst exhibited higher H₂ absorption at a lower temperature with similar trends as observed in O₂ TPD that indicated a remarkable redox property, which is useful for applications as a catalyst in soot oxidation. Excellent catalytic activity with a very low T₅₀ of 358 °C was observed and can be accredited to the improved surface oxygen vacancies and thermal stability by the metal modification of clay.