Efficient CO2 electroreduction on Pd-based core-shell nanostructure with tensile strain

Abstract

• Core-shell nanocatalysts are fabricated to study the strain effect on CO 2 reduction. • The catalytic performance follows the trend of Au@Pd > Pd > AuCu@Pd. • The catalytic activity is positively related to the tensile strain effect. • The increased tensile strain with thinner shell thickness enhances catalytic activity. Strain effect has been utilized to tune the catalytic properties of metal nanoparticles. However, in-depth understanding of the strain effect on CO 2 electroreduction over the core-shell structure catalyst is still unclear. In this work, we report a prominent strain-dependent activity/selectivity in the electroreduction of CO 2 over Pd-based core-shell nanoparticles. Tensile and compressive strain are generated in Au@Pd and AuCu@Pd nanoparticles, respectively, due to the different lattice spacing of Au > Pd > AuCu. In CO 2 electroreduction, Au@Pd exhibits a maximum Faradaic efficiency for CO production of 89.6% at −0.9 V versus reversible hydrogen electrode, which is 1.2 and 1.7 times of Pd and AuCu@Pd, respectively. Moreover, when using Au@Pd with different thicknesses of Pd shell as electrocatalysts, we also find that the decreased tensile strain with the increasing thickness of Pd shell results in inferior catalytic activity. This may be because tensile strain on Pd-based electrocatalysts enhanced the CO 2 adsorption, thus promoting the catalytic performance. This work offers a pathway with the regulation of lattice strain to rationally design effective electrocatalysts towards CO 2 electroreduction.