Implanting Atomic Dispersed Ru in PtNi Colloidal Nanocrystal Clusters for Efficient Catalytic Performance in Electro-oxidation of Liquid Fuels

Although PtRu alloy nanocatalysts have been certified to possess excellent electrocatalytic performance and CO-poisoning tolerance toward formic acid and methanol electro-oxidation, the unaffordable usages of ruthenium (Ru) and platinum (Pt) have greatly limited their widespread adoption. Here, a facile one-pot method is reported for implanting atomic dispersed Ru in PtNi colloidal nanocrystal clusters with different Ru/Pt/Ni molar ratios, greatly reducing the dosages of Pt and Ru, and further improving the catalytic performances for the electro-oxidation of formic acid and methanol. Through simple control of the amount of Ni(acac)₂ precursor, trimetallic Ru_0.3Pt_70.5Ni_29.2, Ru_0.6Pt_55.9Ni_43.5, Ru_0.2Pt_77.3Ni_22.5, and Ru_0.9Pt_27.3Ni_71.8 colloidal nanocrystal clusters (CNCs) are obtained. In particular, the Ru_0.3Pt_70.5Ni_29.2 CNCs exhibit excellent specific activities for formic acid and methanol electro-oxidation, that is, 14.2 and 15.3 times higher, respectively, than those of the Pt/C catalyst. Moreover, the Ru_0.3Pt_70.5Ni_29.2 CNCs also possess better anti-CO-poisoning properties and diffusion ability than the other RuPtNi CNCs. The excellent formic acid and methanol electro-oxidation activities of RuPtNi CNCs are ascribed to the optimal ligand effects derived from the Pt, Ni, and atomic dispersed Ru atoms, which can improve the OH adsorption ability and further the anti-CO-poisoning capability. This research opens a new door for increasing the electro-oxidation properties of liquid fuels by using lower dosages of noble metals in Pt-based catalysts.