Search for: All records

Abstract A relatively unexplored aspect of noble‐metal nanomaterials is polymorphism, or their ability to crystallize in different crystal phases. Here, a method is reported for the facile synthesis of Ru@Pd core–shell nanocrystals featuring polymorphism, with the core made of hexagonally close‐packed (hcp)‐Ru while the Pd shell takes either anhcpor face‐centered cubic (fcc)phase. The polymorphism shows a dependence on the shell thickness, with shells thinner than ≈1.4 nm taking thehcpphase whereas the thicker ones revert tofcc. The injection rate provides an experimental knob for controlling the phase, with one‐shot and drop‐wise injection of the Pd precursor corresponding tofcc‐Pd andhcp‐Pd shells, respectively. When these nanocrystals are tested as catalysts toward formic acid oxidation, the Ru@Pd_hcpnanocrystals outperform Ru@Pd_fccin terms of both specific activity and peak potential. Density functional theory calculations are also performed to elucidate the origin of this performance enhancement.