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.