Site-Selective Growth of AgPd Nanodendrite-Modified Au Nanoprisms: High Electrocatalytic Performance for CO₂ Reduction

Environmental impacts of continued CO 2 production have led to an increased need for new methods of CO 2 removal and energy development. Nanomaterials are of special interest for these applications, because of their unique chemical and physical properties that allow for highly active surfaces. Here, we successfully synthesize AgPd nanodendrite-modified Au nanoprisms in various shapes (nanoprisms, hexagonal nanoplates, and octahedral nanoparticles) by selective metal deposition. This strategy involves coupling galvanic replacement between Ag layers in Au@Ag core–shell nanoprisms and H 2 PdCl 4 with a coreduction process of silver and palladium ions. Synthesis of AgPd nanodendrite-tipped (4.14–11.47 wt % Pd) and -edged (25.25–31.01 wt % Pd) Au nanoparticles can be controlled simply by tuning the concentration of H 2 PdCl 4 . More importantly, these multicomponent AgPd nanodendrite-modified Au nanoparticles show exceptional electrocatalytic performance for CO 2 reduction. AgPd nanodendrite-edged Au nanoprisms show more favorable potentials (−0.18 V vs RHE) than previously reported nanocatalysts for the reduction of CO 2 to formate, and exhibit higher faradaic efficiencies (49%) than Au, Au@Ag, and AgPd nanodendrite-tipped Au nanoprisms in aqueous electrolytes. Moreover, AgPd nanodendrite-modified Au nanoprisms show much higher selectivity and faradaic efficiency for CO 2 reduction to CO (85–87%) than Au and Au@Ag nanoprisms (43–64%) in organic electrolytes. The high performance of these particles for CO 2 reduction is attributed to the unique structure of AgPd nanodendrite-modified Au nanoprisms and the synergistic effect of Ag having an affinity for CO 2, efficient binding of hydrogen at Pd, and Au as a stable, conductive support. In addition, AgPd nanodendrite-edged Au nanoprisms show highly stable catalytic activity during long-term electrolyses (up to 12 h) and repetitive use. These exciting results indicate that AgPd nanodendrite-modified Au nanoparticles are promising for application in CO 2 conversion into useful fuels.