Multiporous structure formation in three-way catalyst particles for enhanced catalytic performance

Abstract

Engineering the internal structure of catalytic particles is an effective approach to enhance catalytic performance. Our group has demonstrated that submicron particles with well-ordered macropores (pore size ≈ 381 nm), fabricated by gas-phase structuring of three-way catalyst (TWC) nanoparticles, exhibit excellent performance in the CO oxidation reaction. However, this macroporous structure limits diffusion within the thick framework, restricting the transport of gaseous reactants to the active sites. To address this issue, secondary macropores were introduced within the frameworks (the spaces between primary pores) of the single macroporous particle via a polymer-template-assisted spray process. Morphological analysis confirmed the successful formation of multiporous structures, as indicated by the presence of both the primary and secondary macropores within the particles. Catalytic performance tests revealed that the multiporous particles exhibit a CO conversion rate seven times higher than that of the single macroporous particles, due to improved mass transport and more accessible active sites facilitated by the presence of secondary macropores. These findings provide valuable insights into the structural optimization of TWC particles for enhanced catalytic efficiency.