Porous Ag/NiO Nanosheet Catalysts With Electronic Metal–Support Interaction for Efficient Soot Oxidation via a NO _x ‐Assisted Mechanism

ABSTRACT

Metal–support interactions play a pivotal role in determining the catalytic performance of supported metal catalysts, yet rational control of interfacial structures remains challenging. Herein, porous NiO nanosheet catalysts were synthesized via a hydrothermal method and applied to soot oxidation. Highly dispersed Ag nanoparticles were loaded onto the NiO nanosheets using the gas bubbling‐assisted membrane reduction (GBMR) technique. The porous nanosheet structure significantly improved mass transfer efficiency during soot oxidation. The interaction between Ag and NiO with different Ag loadings was investigated to understand its influence on the redox properties, and the optimal Ag loading for soot oxidation was determined. The results showed that Ag ₃ /NiO exhibited the best catalytic activity under loose contact conditions (T ₅₀  = 359°C, R = 1.54 μmol g ⁻¹  min ⁻¹ , and E _a  = 84.63 kJ mol ⁻¹ ). Experimental results confirmed that the interaction between Ag and NiO promotes the activation of interfacial oxygen, and soot oxidation proceeds via a NO _x ‐assisted mechanism. This study elucidates the nature of the metal–support synergy in the Ag/NiO system and provides an innovative synthesis strategy and theoretical basis for designing high‐performance soot oxidation catalysts.