Site-targeted decoration of palladium nanocrystals for catalytic CH4 removal in lean-burn exhaust

Abstract

Site-targeted decoration of catalytic nanocrystals is essential for maximizing performance with minimal materials use. Here, we demonstrate successful, site-targeted decoration of palladium (Pd) nanocrystals with nickel (Ni) exclusively along crystal facet edges through the thermal decomposition of nickel carbonyl (Ni(CO)₄) vapor. Strong interactions between carbon monoxide and Pd facet for passivation or between Ni(CO)₄ and crystal facet edges resulted in selective Ni decoration at the nanocrystal edges. The Ni-decorated Pd nanocrystals exhibit superior catalytic performance for methane (CH₄) removal in an oxygen-rich lean-burn exhaust atmosphere, requiring 10 times less Ni decoration than conventional Pd–Ni composite catalysts prepared by the wet impregnation method. The site-targeted decoration of nanocrystals introduced in this work offers an efficient and resource-minimizing strategy for enhanced catalytic applications.